December 2008 really could have been much higher for Wii if they had supplied more, 5m was theoretically possible - thats why Wii sold so well in Q1 2009 (2m) even after doing 5m in Oct-Dec 2008.
Also, I have 2.68m for PS2's best December. But yeah, Wii is the first home console to top 2m in a month 4 times in the USA. PS1 did it twice. I figure NES did it 2-3 times, SNES did it once or twice, and PS2 did it once. Genesis / N64 / GC / Xbox / X360 / PS3 have never topped 2m in a month in the USA.
I wouldn't rule out a 2m Dec in 2011 either for Wii. At $150 everywhere and retailers offering $20-$50 discounts again, the dance games still big and the big holiday game (Zelda probably), it wouldn't be a huge stretch, even if Nov fell to 800k or 900k as the breadth of software for Christmas thins a bit.
People are difficult to govern because they have too much knowledge.
When there are more laws, there are more criminals.
- Lao Tzu







