I think this is all too possible, though my guess was actually 2.2 mil by April. Also, if Reggie said they are going to do it, I'm pretty sure they will. Nintendo pretty much never makes a claim it can't back up. GTA4 would have to be bigger than expected for him to be wrong.
But, hey, as far as I can tell they are saving units up for the same timeframe that GTA4 launches in anyway. Nintendo doesn't want to be beat that week, and I'd be willing to bet that they'd hold off on units now just so they can say that not even GTA4 is potent enough to stop them. I mean, they were all too happy to laugh off MS's use of their 'only bullet' last year, and if you wanted to tell the world that you were number one wouldn't you want to do it by having one of your second stringers (MK is second string for Ninty, at least) lead the way in a massive victory over competitors trying to hawk one of the few 1st string products you don't own?
EDIT: I agree with you, white box. It'd make more sense to fight GTA4, for one thing, but also there is the fact that if WiiFit follows the trend of many other casual games made by Nintendo (like Brain Age) then it's probably not going to be that big of a deal, actually. I could be wrong, but to me it seems that exercise is just as hard to sell to my follow Americans as thinking is, so I really expect Europe and Japan sales of that game to look pretty good next to American sales.
You do not have the right to never be offended.
