I think a couple of factors will come into play.

A) Whether or not MS can improve their current image. Its pretty well known that the 360 has unacceptable reliability. If the can get the new 360 out the door and fix that image it will help them a lot.

B) Another price drop. I assume they are waiting for A) before they do B) since selling the current 360 will only amount to financial loses. If they drop the price another $50 with the release of the new 360 then even I might get 1 even though I dont care for Halo.

If the above happens:

+/- 0 (it will be even with the Wii for about a month)

If the above doesnt happen:

- 100k (sales will double to around 100-120k per week but will not catch the Wii)

Will

+65k 

This is my first prediction, so I'll take it calmly.

I believe the Xbox 360 will ride past the Wii in North America, but not in Japan. My say is...

The Xbox 360 will not pass the Wii worldwide. Difference: -65,000

There.

My brother and I are buying a 360 just for halo 3 but were going to try to get it acouple weeks ahead.

I think it will pass by +15k

The game will, but the hardware might not follow, at least significantly.

Some of the claims are ridicules. Some people think really that the 360 (At the moment 60 k a week WW) will get a boost of 300K console in one week? The Game will sell, it will sell like shit. But in the first week you will get it most likely only if you have "pre orderd" it. I mean how many units you expect will ship in the first week? (Ship most likley will be sold)? 3 Millions? With that number means that 10% of the games are sold with a SKU IN THE FIRST WEEK.

Sorry, thats just to much. No doubt that game will move hardware. But thats just to much for the first week.

Through the roof? No. Raise the ceiling? Sure. Unless the game gets seriously bad word of mouth before hand. So long as it gets decent reviews, it'll sell some boxes.

I believe that Halo 3 will raise purchasing a little. I don't believe it will be ZOMGWTF huge, but it will be an increase for sure. It will at least bring them back up above the PS3 sales for a while, unless Sony is more aggressive with their pricing.

However, I am also predicting that RROD incidents will increase by 200% after the release of Halo 3. Elites, Cores, and Premiums will begin dying in droves.

Edit: Mr. Moore said, before he left MS, that there would be an Xbox 360 special edition SKU that is bundled with Halo 3. It wont be a permanent model, but it will be a special (yet pricey) Elite that has a Halo 3 themed skin plate and bundled with the game.

I believe it will move -those- systems and will incease overall sales for a while. However, like many people have already said - Alot of Halo players already have an Xbox 360 so it may or may not be the messiah for the 360. If it isn't....

However, I will not gauge the 360's success in this push based on the sales of Halo 3. The system will surely be put to the test when the dreaded age of "Life after Halo" descends upon the 360 players.

If there was a deal to get Halo 3 free, or close to it, with a Premium system...I'd buy a 360. I'm sure there's a lot of people that are just waiting for a good price on the thing...

I hope you know what you're saying here.  You are basically saying 360 will sell around 450-475k in 1 week.  Last week it sold 53k WW.