After 4 weeks, 5,1 millions.
LTD = about 20-25 millions.
I don't get why some people think that it will do less than 15 millions. I have even seen some people saying that it would do less than 10 millions and even less than Mario Galaxy. That would be a failure for Nintendo.
NSMBWii beating Mario Galaxy is a given, 2D is much more popular and the Wii users are much more now.
I think that the game will do like Mario Kart Wii. It's probable.