Not easy to say
Wii is now at 5.37m in Japan (5m at Smash launch?)
I expect PS3 to be next to 4 million at the end of the year.
I expect FFXIII to get a similar or better first week than Brawl but worst legs
Brawl: 3 million
FFXIII: 2.5-3 million
Oh, and what do you expect of PS3 hardware when FFXIII arrives?