A sliding screen would be terrible. The lower screen is as large vertically as the top screen. On something as big as the DS, the top will be huge and this ungainly to support holding only the bottom since it has to slide up it's own height (same height bottom). You would also not be able to look at the top screen closer to head on (it must always be on the same plane as the bottom screen) which is harder to play for extended gaming. Lastly, there is even less room for the analog slider that way, and it's nice large size is a big advantage over most portables. A top screen that is visible when the unit is "closed" is only useful when you want to look at the top screen playing something while not needing any controls (except L R) which for the most part will only be non gaming (though there is tilt...). It's fine for a media player, but a bad idea for a gaming handheld.
That said, I do wish the 3DS looked less like the DS. More changes would help cement that it is a new system instead of a new model. I can't think of anything better, but something different would have been nice.
WiiU - Vectorferret
