I think people are vastly overestimating this and setting themselves up for disappointment. 80K week one, 67K week 2, and 50K week three. Where it goes from there depends on a few factors. I would guess we're do for a Wii Sports Club hard copy around June-July, Bayonetta for September, X late October (Japan at least), and the flagship NFP game in October for the US. Hyrule Warriors also seems like a possible Fall title. Those should be able to keep sales at around 50K, give or take 10K a week. Holidays are kind of up in the air. It's seeming increasingly more likely that Smash may be the only huge holiday release, which would not be good.
Of course, I'll be happy to be proven wrong. Who know, maybe sales will rise to 100K per week.