I see a ban coming for one troll-worthy newcomer to the thread. The poster who names himself after sex with a female dog. Interesting.
Let me respond to the people mentioning Wii's current sales figures as an impossibility of my prediction coming true.
Halo's opening week tally will be finalized after that week is over, right? It will probably be around 4 million worldwide opening week. Everything AFTER this opening week does not go on the Halo 3 opening week total because...it's not opening week.
CURRENTLY as of October 4th Wii in Japan according to VGC has 3.66 million sold in Japan.
Why do you think this number will stay constant by December?
You know good and well it won't and the holiday season will spur on tremendous sales which is why I made those bold minimum 20 million worldwide end year claims on my first post here way back in March right before St. Patty's.
You gotta remember something. Wii worldwide sold just under 4 million by end of 2006 (GRRR! Wii strap recall!) in less than 1 1/2 months. It launched in the Americas on November 19 giving it only 43 days to contribute to that amazing figure. In Japan it launched on December 2, just under a full month, giving it 30 days to add to that fantastic figure. Because of the Immaculate Conception different regions of Europe got different launch days with some getting it on December 7, some on December 8, and some on December 9. So this respectively only gave Wii 24 days, 23, days, and 22 days to add onto that fantabulous figure.
It's not like that this time around and the Wii will have exactly the same fervor if not more this year than last.
You got 3 full calendar months to create powerful hardware sales for all regions. It's even launched in South Africa now finally! No China yet but they're bootlegging it with Vii anyway. Haha.
October, November, December. The traditional holiday buyer season months. People start gathering presents for loved ones at this time. I got my NES on Christmas 1988 and my grandmother bought it in October keeping it locked away until XMas day. Love my grandma.
Wii hardware will climb tremendously in the next coming months. That Japan 3.66 mil is not going to STAY 3.66 mil. And of that amount of all owners I see a tremendously high attach rate for this system in regards to Wii Fit. It appeals to the new audience in a whole new light. Have we EVER seen anybody merge the chore of exercise with the fun of a game and do it well? I think Wii Fit will pull it off and believe you me unlike in America where ads on this may not work quite the same, it WILL work in Japan and I bet you they are preparing Japan to get hyped up for this new direction. This will be the Brain Age/Nintendogs effect that fully turns on the Wii potential like Brain Age/Nintendogs did for DS.
Wii's only been playing with the competition so far. The heat is about to be turned up and Wii Fit is part of the equation that will make this happen. This game will eclipse everything for a long time chartwise. Giga Bowser Kaioken X 50 Ascended Super Duper Saiyajin with a cherry on top AND the bag of chips.
It's coming. And all I'm doing is getting you ready for it. Stay tuned, baby. 
John Lucas