A high res screen. Even the most beautiful games just look awful on that tiny thing. Smartphones and the Vita and basically everything that's not a 3DS all have a huge, gorgeous high res screen, and I'm getting sick of playing games that look like a blocky mess. I would even pay for the same graphical power again if it could just output at a higher resolution.
Two sticks and better battery are up there too. But damn, that screen. Here's hoping for an HDS.
Currently playing:
Bloodbath Paddy Wagon Ultra 9