Wii's top week so far was 1,474,433 units right before Christmas last year. That's definitely not going to happen. 
For non-holiday weeks, it's possible we might see a new record. Wii's top week so far is 458k, from the week of 21 March 2008. That will be something to keep an eye on, although it would require something like 250k America/200k Europe/50k Japan to pull it off. Interesting side point: aside from holidays and the PS3 European launch, neither the 360 nor PS3 have ever topped 250k weekly. So we may see a new record for one of them too!
And yes, of course Nintendo is trying to compete with Grand Theft Auto by releasing its games the same week. This whole "they're not actually competing with one another" is pure nonsense. Fortunately, the gaming market is large enough that all of these big games will be able to draw healthy sales, and turn big profits.
End of 2008 totals: Wii 42m, 360 24m, PS3 18.5m (made Jan. 4, 2008)
