I'll post what I put in a similar thread a while back:
What I want/expect: Roughly 2-2.5x 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)