Boney said:
3DS launch from Nintendo is Kid Icarus, Paper Mario, Nintendogs, Steel Driver and Pilotwings. With Mario Kart, Zelda and Animal Crossing soon to follow.
From what I can see, it's not that much of an effort. Shouldn't really cut into their output significately.
Here's what we know is in development from Nintendo for the 3DS:
EAD 1 (Mario Kart, Nintendogs):
Mario Kart 3DS, Nintendogs + Cats
EAD 2 (Animal Crossing, Wii Sports):
Animal Crossing 3DS, Pilotwings Resort
EAD 3 (Zelda series):
Ocarina of Time 3DS
Comprehensive Software Development (Pac-Man vs., SM64 DS):
Star Fox 64 3DS, Steel Diver
Intelligent Systems:
Paper Mario
Project Sora:
Kid Icarus
EAD 3 is also working on Skyward Sword. EAD 4 is doing Pikmin 3. EAD 5 is/was probably doing Wii Relax.
Retro's finishing up Donkey Kong Country Returns. They won't be able to do anything in less than a year for a system launch or launch window. Monolith is kinda in the same boat, but has more of a shot.
The only ones that we know aren't busy with known projects are EAD Tokyo, Nd Cube, Genius Sonority, maybe parts of Intelligent Systems, and SPD1.
SPD 2, Brownie Brown, and NST might be available, but those are all handheld teams these days. Point is, the big guys, EAD 1 and 2 specifically, are too busy right now finishing their 3DS games to also be getting ready for a new console.