I would like to see enough power to emulate the N64, Sega Saturn, PS1 or even the PS2...
In addition to that I like to have the easy possibility to mod the Ouya 2. I like to get the Ouya 2 in other Cases and solder USB-Hubs and stuff directly to the board without big problems. The actual ouya did there a great job... It wasn´t a problem to solder the USB Hub to the board or replace the power button... that "features" have to stay!
A 100% USB compatibility would be nice... I dont want to try out 10 different USB-Hubs again to find the working one...

And of course... the software have to be 100% backward compatible...