I don't quite agree with you, mrstickball, although I also happen to think that Halo will probably end up with 10m lifetime sales. I just think that Galaxy will ultimately end up higher than that, with a lower attach rate but higher overall sales due to the Wii's rapidly growing install base. By the end of 2009, there could be 60m Wiis out there compared to 30m 360s, and THAT is when you'll see Galaxy sales exceed those of Halo. Obviously it's all pure speculation at this point, of course. 
I disagree that Twilight Princess should have done better than it has so far; it's closing in on 4m sales, and don't forget there were another 1.3m units moved on the Gamecube as well. Obviously you can't just add those numbers to the Wii sales, but at the same time there were definitely a fair number of people who couldn't find a Wii and therefore bought a Gamecube copy instead. Twilight Princess sales hold up fairly well against, say, Gears of War (4.8m) considering that the 360 had a humongous install base lead for most of this past year. Don't forget that Twilight Princess sold just shy of 25k this past week in America, and almost made the top 50 on the chart!
You're not going to make a lot of friends here by referring to Mario Galaxy sales in Japan as "abysmal." Dewey's Adventure sales were abysmal; a game that sells 1m+ is definitely not. That was probably not the best choice of words.
End of 2008 totals: Wii 42m, 360 24m, PS3 18.5m (made Jan. 4, 2008)
