Platforms I think: PC Mac Linux Wii 360 PS3 (Difficult but not for YellowDog Linux Consoles) PS2 (Old but widely used and easy to run homebrew) PSP iPod Touch / iPhone
All of them seem possible to me. But then again I'm no programmer.
So I'm back and here is my opinion: everything is possible but you have to think about the power of the platform. on a psp its possible to start and "play" the game but it laggs like helll. same on the wii. so i think it will be hard to get it to work without lagging. so on with the other consoles / platforms: if i had one of them you can bet your ass that i would try to emulate toonstruck on it ^^...but as far as Im now i will try to improve the wii version (when i have time for it) and perhaps a short video of me playing it :)
Now that ScummVM supports Toonstruck it should be easier to run it on strange platforms, because DosBox (and thus the x86 emulation) is not needed anymore. Even if Toonstruck on ScummVM is still too slow for some platforms (I don't know.), there's hope it gets better when the Toon Engine in ScummVM is improved (right now it updates the whole screen on each frame instead of just the parts of the screen that have been updated.. that's quite "expensive" of course).
3DS might very well be possible for a port everyone! The eShop is supposed to support third party developers once it's released, allowing indie games to be able to put there games up.