Current lifetime shipments (rounded)
Wii - 95m
X360 - 66m (29m gap)
PS3 - 62m (33m gap)
2011 shipments (rounded)
Wii - 10m
X360 - 15m (5m gain)
PS3 - 14m (4m gain)
Going by previous years, Wii is dropping at the rate of about 5m a year. FY08 25 > 20 > 15 > 10. Now this doesn't mean 5m is a shoe in, but anything over 7m is unlikely, given those yearly drops, even less SW this year than last, X360 cut (First in what will be 4 years, Kinect bundle at mass market price) and possibly a PS3 cut (mass market price finally) along with WiiU.
PS3 and X360 could and may well slump as well, given they have a steady stream of SW, significant cuts to come, and no successor coming out this holiday, it's unlikely they'll drop as hard as the Wii. I guess anywhere from 12 - 15m for both. So potential of 5m - 10m gains for PS360.
2013 onwards it's guesswork how all 3 will do.
I reckon both will come within 15m of the Wii though.
