first of all in the next generation we probably see ps4 with ps3s cell or slightly-improved cell, because cell is enough powerfull to pull of great graphics. sony will definitely bring beter(and faster) gpu, ram and so on though because those things "slow down" ps3.
as for x360 we will see again hi-end console that will be able to pull this magic 1080p without any problem.
wii 2, well i think that nintendo will make again 200-250(with a game) console so i guess it will have:
2.8-3.2ghz processor or somethin near it,
won't be able to handle 1080p but will have enough specs to pull of 720p on 60frames/s without any problem,
256mb ram for console(both gpu and cpu),
2-8gb harddrive,







