I predict a new DS design this year or early next year

[Grey Acumen]

I think Nintendo does already have a plan that will involve completely getting rid of the GBA slot, and probably using that to put in a bigger stylus, however, i don't think they'll release it until they see something like the PSP2 or when they see the DS actually start to slip in sales significantly. Personally, I think Nintendo is curious to see just how far they can run with the DS and Wii, and there's barely been any Wii/DS functionality implemented.