If I was a betting man, I'd say Wii would get there first, unless Microsoft drops the price of the 360 sometime in the summer. They are saturating the market at $400. If they don't crack 200k in the 5 week NPD of June, and still don't drop the price, Wii will get there first easily.
Threads of Interest:
The Movie Thread: http://www.vgchartz.com/forum/thread.php?id=6880
The Crow Eating Thread: http://www.vgchartz.com/forum/thread.php?start=0&id=3886
The Betting Thread: http://www.vgchartz.com/forum/thread.php?start=0&id=7104
Custom GIFs Thread: http://www.vgchartz.com/forum/thread.php?id=18963
The Greatest Game Ever Conceived On Any Platform
Tag: "I have tasted Obi-Wan's bitter tears"