It's not two screens like you would think!
The 2DS, that's a thing! It's aimed for a younger audience, and it cuts out all the 3D stuff. And as it turns out, those two screens are actually one big screen. That's according to US Gamer in an effort to cut down costs. The appearance of two screen is a simulated one, and the case is designed to make it look like two whole screens like the 3DS.
So yeah, even the upper screen is technically a touch screen, but it's protected by a layer of plastic. Plus, there's no game that would recognize that the top screen can be an interface now. That said, it'll be interesting to see how modders rework the 2DS.
Oh, So That's Nintendo's Next Move [USGamer]