No, just take a good look at Bioshock!!!
Bioshock 2 PS3 Xbox 360 combined sold less than Bioshock on 360 alone! Sometimes multiplatform just won't do the trick!
I would expect Mass Effect 3 to sell less on 360 (less the 2 million), and combined less than 2.4 million.
And of course Mass Effect 2 PS3 to sell around 0.3 million in a year, just like Bioshock PS3...







