Seece on 26 September 2010
Going by what we know
LittleBigPlanet 2
Killzone 3
Last Guardian
InFamous 2
Zelda Wii, very possible. Although both Gears games have settled above the highest selling Zelda, there is still a good chance.
Modern Warfare 3, if it comes out, which is probable, then yeah this'll beat it, on X360 alone.
GTAV, again if this comes out it'll beat it.
Pokemon Black& White western release, yes it'll beat it.
I do see Gears selling around 5 million in 2011, given Gears 2 selling 4.3 in it's 9 weeks of 2008. Actually 5 mill is lowballing it given it has an extra 26 weeks of sales. Depending on it's launch (it can be improved upon imo) 5.5 isn't out of the question, meaning it'll put up a pretty good fight.
