The Official NPD Feb 2011 Thread (Data in 4 hrs for 4 weeks ending Feb 26)

[Nintendogamer]

Acevil said:

ethomaz said:

From GAF.

Donkey Kong COutnry Returns: > 2 Million Lifetime U.S.
New SUper Mario Bros Wii : > 8 Million Lifetime U.S.

Nintendo themselves stated that in a statement. They also gave other numbers like SoulSilver. 

Vgchartz has it at 2.331M,  so 2.331 * 0.86 makes 1.98M, quite close.