I wasn't worried about SMG sales, so I'm not sure the reason for the thread, nor why it is being roped into a debate on SMG vs HALO 3, but since I'm avoiding work, I'll toss in my 2 pennies...
Some of the factors that I think is important to remember:
1) Halo 3 was incredibly frontloaded. It's like modern movie blockbusters that hype the shit out of their product and then drop off dramatically. Mario Galaxy was not sold in the same manner - it practically snuck onto store shelves.
2) Mario is simply the single most recognizable character in video games. Even casuals know him, and will be likely to pick up the title if the reviews are good enough (and they have been), so the "core vs casual" thing shouldn't be as much of a factor as it would be for some other franchises.
3) Mario's appeal is truly to all ages, and the Wii's numbers are growing faster than the 360's. In a year, I expect the Wii to have a 2:1 advantage world wide. Those 2 factors mean the Wii will have a much larger user base than the Older-Core-Gamer oriented Halo 3.
4) There is no shortage of good shooters on the 360. Hell, there's a bunch of good games this holiday that will give H3 a run for it's money (COD4, Mass Effect, BioShock, etc), but SMG is pretty much in a class by itself on the Wii. No other platformer is half as good (and if there were, they don't have the name recognition), and there aren't many titles in other genres to compete with either. In short, for the next few months at least, anyone who buys a Wii and asks "What games should I get?" will be told, first and formost, get SMG.







