Clamshell:  I like the clamshell design for games since you are holding and looking at it so convinence for your pocket is not as important as it is for an ipod.
Two analog sticks:  If you are gonna have 3d games, you need two analog sticks.
Digital distribution only
Made by Nintendo
4 face buttons and the d-pad from a SNES
widescreen with a resolution of 480p
Actually the DS is pretty damn good.
So take the DS, make the screens a little wider, higher resolution and put in a couple analog sticks and you are done! thats it you heard it here first, DS2 coming fall 2010.