wii sold 5.8 million last year but if it had the supply last year it could have sold million more obviously, it was selling at an average $430 on ebay. This year will probably be the peak, meaning the demand will likely be even higher this year, so it should all depend on supply, 10 million is completely reasonable if there is 10 million to sell.
360 is likely going to stagnate, but it should be up slightly year over year, and a price drop could shake things up a little bit.
ps3 i think will be up by around 50-60% year over year.
So i'm gonna guess:
Wii 9.4 million
360 3.5 million
PS3 4.8 million