It already has...
5 weeks ending 5th January 08 = 4037K
As for this year, Wii will sell 4M in just 3 weeks. Chances are it will sell over 5M in the 3 weeks starting this one (VGC). 6 months for the 4 weeks, and possibly 7M for the 5 weeks.
So yes, by a long, long shot. Heck, it could make 4M in two weeks, which is less than half a month.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS