I'd say 3D is a main selling point, because it is a standard for that console. People need to get used to the 3D because that's the best it is right now, and will be for a while. The 3D comes built in vs. buying a seperate TV.
PS Vita may be cool to some, but I've played it at kiosks, and the buttons and controls are all over the place, all while being cramped. The games aren't even that great, and I was playing Little Big Planet and PS Battle, which are some of the biggest titles out for that handheld.
As much as I hate to be a killjoy, PS Vita is horrible to me in everyway. Price point, controls, games, etc.

The 3DS had poor launch numbers because it launched without a compelling piece of software that lots of people could get behind. Let's also not forget that Pokemon Black and White came out right before the launch, as well. If the system launched with 3D Land, Zelda, and an exclusive Pokemon game, things would have been different.

As for the Vita... I'm not entirely sure when it comes to launch.

For Angry Birds, I was talking casuals and the stupider of the hardcore. The most hardcore audience... I don't know? Gaming laptops? But those get a bad rep as well.

I feel like PS Vitas similarity to PS3 is what killed it. There is no reason to have both of those consoles if you have one IMO. I have a PS3, and I have no reason to buy a PS Vita. It's been out for a year, and has nothing to offer like 3DS did within a year.

I like the 3DS. It's like Hugo said, less powerful than other consoles, but I already loved the DS before that so I don't really mind that. It's actually quite impressive to me and a good successor to the DS. It's like.. the DS 2, a little bit more powerful and advanced, but still simple... The 3D? That's just an extra, you don't really need to use it at all, and developers certainly don't need to implement either, they're free to make their games 2D if they want to, I don't really see what's the problem with that.

Nothing the DS did was really impressive or unique either and it was much more limited than the 3DS, but it still was a great success.

About the DSi, it is my favorite member of the original DS family, and I have had every DS model.

Not to get too side tracked, but the failure of the Vita largely stems from mixed signals from Sony. I picked mine up in May (the base Wifi model with a four GB card and Unit 13 tossed in for $250 US) and really enjoyed it. Gravity Rush was excellent. The Resistance game made me vomit uncontrollably, but as a general rule I liked the console.

But then out came the weird signals. Sony really began to emphasis downloadable releases. Which is fine, but eats up valuable expensive memory card space. The Cross Buy promotion was a great idea. Until you realized that 1) some of the games required as much as a third of a 4 GB card, even prior to patching (Last time I checked, PSBA used up 1.3 GB?) and 2) It still wasn't implemented properly (See: Ratchet and Clank: Full Frontal Assault). Point 1 can be remedied with the purchase of a new card, but now we're looking at purchasing multiple relatively inexpensive cards or a massive expensive one. At that point, you might as well have purchased the retail version of the game. For the system to have worked well, Sony would have had to cut down the price of the cards to a pittance. I don't mind spending $20 on a memory card, but not when it will only hold one downloadable release and one digital retail release.

It'll likely follow the PSP model. The launch was fine, then there was a major drought, then it rained games, then there was a major drought, then it rained again, then the land became too unstable to cultivate and nearly everyone left.

I think they used the DSi as a testing ground of sorts for features they were looking into implementing into 3DS. I don't really think that it had too much of an impact on sales of the 3DS though. I think the biggest problems, as others have said, were the lack of games and the cost. I think the fact that sales of the 3DS jumped 260% after the price drop confirms that many people's main reservations were related to the cost.

I think that was the psp's problem as well! People want a handheld for a different experience and that's what Nintendo offers. We don't want to play our console games on the go but that's quickly changing! Look at monster hunter coming out here soon. The cross play between them both could be considered by some as exactly the same game. Not to mention the wii U's game pad already seems like to some a portable and console in one. I'm sure some people think they can take it anywhere. I'm getting off track here a bit though but the point was if I can play it on the big screen then why would I want it on a smaller screen.

@SCAR392 (Post #21) - Nah, I don't see 3D TVs becoming the more "in-demand" high-tech TVs when compared to 4k. Most of the 3D content on those is pre-rendered (or added in post-production), which doesn't look as good when compared to the 3D effect used in 3D games. Just look at SM3DL's 3D compared to just about anything on Nintendo Video. Unless media companies begin producing SM3DL-ish 3D for movies/TV shows/whatever else, it just won't draw people in.

As for the initial question: I don't believe the DSi killed the 3DS's launch. That extra processing power in the DSi did exist, but it was never marketed well (I'm sure almost nobody remembers it at all). Even still, because DSiWare development never really took off as companies looked to continue to market to the larger base of DS owners over DSi owners, that extra processing power would need to be nerfed so DSi-enhanced (black cartridge) games could still run on regular DSs, making it fairly useless, and DSiWare developers never even used it (maybe those small indie-ish 1st/2nd Party games on there and WayForward used it), that really didn't make any kind of impact. As for the confusion between the two similarly names consoles releasing in two years, that makes absolutely no sense. Cell phone makers release new, similarly names models annually (sometimes even more frequently than that), and I don't think anyone gets terribly confused about that, so I can't see that as a problem. Sure, numerous people did get confused by the 3DS's name (I've heard it be called a "3D DS" numerous times) compared to its predecessors, but I think with the heavy saturation of demo models available in stores, people could see that it was "different enough" from past DSs to prevent that confusion. And if they didn't, they probably weren't planning on buying one in the first place.

The real culprit behind the 3DS's launch failure has been explained numerous times already: High price and no games. Shelling out $250 for a game console that could do so little when compared to its main rival, smartphones, at a similar price, combined with the majority of the "system-selling" games/franchises like Mario Kart not available to purchase, drove many consumers away. It was only until after the price cut and the arrival of titles like MK7 that the 3DS became attractive to many consumers. The DSi did little, if anything, to impact the high price (which came as a result of pre-release outlets foaming at the mouth about it after seeing the improvements in it when compared to the 6-year old DS line) and lack of good games (which was a poor decision by Nintendo to let 3rd-Party titles shine during the 3DS's launch).

@Birdman
Are you kidding? ALL 4K tvs are 3D.

What did you tell them?
DSi killed the 3DS launch.
DSi killed the 3DS launch.

^That actually fits the right number of syllables. Damn, someone make a full parody.

+1

What are you guys talking about?
Besides, I wanted a 3DS regardless of price. I was planning on getteing one on launch, but stuff came up and I ended up getting it after summer for $120 with the ambassador games.

As my launch day 3DS I paid $250 for is getting in worse and worse condition and I am unable to sell it for a decent amount of money to upgrade with, I see this post. I am pretty mad. Not at you though, because I'm a cheapskate like that sometimes too. More at Nintendo for making the original overpriced and with bad build quality.

You should've done what Microsoft fanboys do and replace it every 11 months.

Well at least they can with a user account and not 5 total transfers!

The launch was not terrible in any way.
As a matter of fact, the 3DS is the most pre ordered console ever. It was the post launch that was awful.

There were plenty of reasons why the 3DS did bad for the first few months
1. The dangers of 3D was overexadurated in the media.
2. The price was amazingly high for a Nintendo Console
3. Mobile gaming was/is a major wreck for dedicated consoles everywhere
4. The 3DS was confusing to fully comprehend the difference between DS and 3DS in advertising
5. No Mario/Must haves. When Ocarina of Time came in at June, we saw a massive increase of sales for a few weeks.
6. Many people were curious to what Sony had planned for the NGP (Now called the Playstation Vita), and stuck still with their money. It didn't help that the console costed the same price as the 3DS at the time.

Really? Where?
All I heard is nothing but speculation & a misinterpretation of a quote of Satoru Iwata.
Other than that theres no straight out comment from Nintendo nor any developers that mention any boosted processor speed.
Don't forget that the DS line (also 3DS line) have both CPU's combined into a single custom chip so it would add time to the systems development time to come up with a new one.
From the Wii's 2006 release to the DSi's 2007 E3 reveal with working prototypes It's safe to say that most of the development be on the software & any off the shelf updates like the double RAM, storage for the DSi ware & updating the wifi to 802.11g & a pair of camera sensors simular to the DS's Face Training camera attachment.

As for allowing improvements for software I haven't seen anything improvement other than minor that can be explained otherwise.

Korg DS10+
It uses the extra memory to load the extra samples in.
Something that can be done with the regular DS if they used the DS browsers memory expansion

DSi Browser
It is faster than the DS counterpart which is true but thats as mostly due to it's using a newer version of Opera with a faster rendering engine.
Plus the unified 16MB of ram of the DSi could have helped as opposed to the DS browser having to use the 8MB add on to boost it to the 16MB.

As for your example with wayforward titles I seen nothing that a regular DS can't do fact I seem simular effects used in regular DS games

So as it is the DSi very short development time & with no software to show for it it's basically show for itself that the DSi just like the rest of the DS line has the excact same 67 MHz/33 MHz CPU combo.