Hmm, fair bit of overtracking :-/
3DS 750k overtracked in US according to Nintendo, they provided SW updates as well.
Mario Kart 7 at 1.3m (260k overtracked), SM3DSL at 1.7m (430k OT), LOZ:SS 1.3m, 130k OT
X360 looks a fair bit over as well 400k~
Perhaps next month we'll see some adjustments to NPD, something definitely seems fishy. Nintendo announced 39m with last Dec NPD, but so far total lifetime is at 38.9 with January.