There's been talk about how the 3DS could have some connectivity features with the Wii U. Miyamoto even said that the 3DS could be a convenient Wii U controller (http://www.nintendolife.com/news/2011/06/miyamoto_3ds_could_be_a_convenient_wii_u_controller). There's also the confirmation that the Super Smash Bros. games will feature connectivity between the two platforms. How else could a brilliant feature like this be used?

Yeah could be a plus for both systems

The only thing I want is to be able to play The Legend of Zelda cooperatively with someone like it was on Wind Waker with the Tingle Tuner. My sister would play as link while I was on the tingle tuner being an idiot and wasting her rupees

Nintendo is copying Sony again
The PS3 can do that with the PSP.

This why Nintendo is always behind, just like their baby games.

Ah yes make firewood, and branches work together best idea ever, way to go nintendo total genius you copycats you.

....sees Lord and Lady
Wtf, there's two of them now? o.0

Oh looky, the Gamecube and GBA say hi

It looks like we've got some serious trolls hating on the Big N. When will the kiddies grow up? They've brought the kindling to make a nasty fire.

@LordIZ

Sony Pocketstation says hi.

I like to see game functionality between the two mostly. :] And maybe some way to connect and check ur messages on ur Wii and updates.

I'm going to be honest and say that I have never owned or heard of Sony Pocketstation, but I just did some research and I learned that the Japan only system connects to the PS1 only to function as a memory card.

Bahaha I find this quite enjoyful.

They have used these things already but I hope they use it even more. Pokémon games are a good example how the handheld - home console connection works. Geometry Wars: Galaxies also had some features, you could unlock one galaxy in both games by pairing up DS and Wii version, and you could also send demo from Wii game to DS. Actually, now that I think about it, all the demos for DS had to be sent from Wii...

EDIT: There are too many Lords around here...

Didn't the N64 pull this off first? You know, Pokemon Stadium and that controller attachment thing.

A sign apparently posted at Sony HQ in Japan: What Nintendo makes, We take.

With the circle pad pro, u could have a controller for super smash bros easily, im thinking gamecube controller by the way, and a wii u controller too. It has all of the buttons and everything, including an extra screen.(3D one)

You hate Sony so much, yet in your signature you say you want a PS Vita. Hypocrisy at it's finest.

I plan to get both systems some time this year so if I could use my 3ds as another controller I'm happy with just that....

Do you think it would be possible to stream 3DS games to the Wii U, similarly to the GameCube and GameBoy feature? I thought it was a neat feature and I'd like to see it used again...

I'd say that's highly unlikely.
A lot of games looks great on the 3DS, but if they were displayed on a large TV instead then they'd probably look terrible.
Plus at this stage they don't seem to be doing anything with 3D for the Wii U which would make the 3DS's main feature non-existent when played through the Wii U.

Using the 3DS as a controller could prove useful, but playing 3DS games through the Wii U wouldn't really work I wouldn't think.