What I want:
Roughly 2.5x as powerful as PS3, with more RAM
20gb storage, expandable
unified online system
SEGA MD CD, Saturn and DC games on the VC
GC and Wii full backwards compatibility
Games come on a disc media based off Blu-ray or HD-DVD
Somewhere between the size of the Wii and half again as big
Retail in the U.K for roughly the same price as 3DS did originally - £230 ($375)