Obviously some like Super Mario 64 DS may be too large to be downloaded but I am sure some would be small enough to be downloaded.

Okay, you might still be able to find games like Pac-Pix in the shops still but it would be no different to XBOX 360's Games on Demand service.

That would be great. I mean, the PSP Store has some PSP games for download _{Megaman Maverick Hunter X ftw} but seeing as Nintendo has never done it before, I don't see them doing anything like that in the near future.

Won't happen, but i wouldn't mind it.

Sure why not.
Maybe that way they could finally release Tingle's Rupeeland to the US without fear of losing money since it's not a physical copy of the game.

I think it would be a great idea to release some older DS titles. I'd love to see some older games that are hard to find.

Aren't they putting like every Sonic game on DS on eShop?

Um...where did you get that information?

No. As it wouldn't be Virtual Console but Games on Demand. Also If nintendo does a future update to play from the SD card then its possible no matter the file size.

VC games play from the SD card already

Like @lz20XX mentioned, all 3DS data is automatically stored and streamed from the SD card, so provided the games run through that method and not like DSiWare, file size isn't an issue, unless the game is so effin' huge it breaks the download size limit eShop downloads might have.

Super Mario 64 DS is like 13MB large......Let's Golf 3D is like 200MB....there's definately no problems with file size anyway.

But they probaly want to exhaust GB/GBC titles first, before moving onto GBA...and eventually DS.

that would be so awesome

Isn't that sort of what's already happened?
Except they split it pieces so you have to pay multiple times.
(Electroplankton, Domo, From the Abyss)
And that Red Riding Hood BBQ thing or whatever it was that supposedly was a retail game in the US (haven't seen it myself except online, and I've looked through the bargains bins pretty regularly) and DSiWare release in EU.

Not at all, it's actually one of the smaller games on the system (sitting at about 8-16MB). Even stuff like Animal Crossing is around 32MB (under the WiiWare limit). Aside from a few obscure Japanese games and such, the largest DS games are Pokemon Black/White, sitting in at roughly 256MB. Even that might fit on the service, seeing how Let's Golf is 195MB.

Of course, this is speculation since we don't know Nintendo's limitations, but it's not an exaggeration to say over 2000 titles would be eligible if we're talking under the size of Let's Golf.

They already have. Red riding hood's Zombie BBQ was a DS game.
Don't see why others wouldn't be possible.

Sujin Taisen was another retail game that they put onto DSiware. It was better on DSiware infact because its a great online game and the original card didnt use the new wifi settings on the DSi (and the 3DS) whereas the DSiware version had been updated.

http://dsiware.nintendolife.com/games/dsiware/sujin_taisen_nu...

It's almost a certainty that this will happen, but with older handheld titles being all the rage on the VC service, I doubt that we'll be seeing any downloadable DS titles until later in the 3DS' lifespan (and if not then, then sometime during the next handheld generation).

All I know of is the Game Gear games.
Would love to have Sonic the superior to genesis version hedgehog 1, and Triple Trouble, but the rest can rot.
I'd like Sonic Advance 1 ( AKA the TRUE Sonic 4 ) to see a release someday...

Couldn't that have been said about the VC service in general? I for one could see this happening.

Sure why not?