Since we don't know what the new Nintendo 3DS looks like, people are having to guess what it looks like. Some guesses are crimes against nature, but others, like these, look pretty good!
Most of these are mock-ups from users over on gaming messageboard NeoGAF, and unlike the flights of fancy that plagued the internet prior to the release of the DS and Wii, these are sensible, and even occasionally stylish renders.
For what it's worth, I've thrown our own DS2 concept from a few months ago in there, but now that we're all a little older and a little wiser, the idea of both screens linking together in the middle seems like the best way to go about things.
Nintendo 3DS mock-up collection [Tiny Cartridge]