I think this talk of this title will boost sales and this title will boost sales is silly. MW3 not going to do much, FFXIII-2 not going to do much, etc. etc.
Sure a special edition console may cause a small increase in sales, but for the most part they just increase profits not sales. Maybe a week or two bump thats it. Software particularly sequels/prequels are done pushing much software. This time of year it comes down to overall support and market excitement.
In US 360 is now what the people are talking about, the PS3 price cut will help some this year, but the 360 now has the excitement factor. All people care about now with software is is the platform being supported. 360 and PS3 can definitely say yes to that question. 360 now has the excitement of the casual Christmas gift purchasing crowd with Kinect, and unlike last year they wont run out of supply of 360s and Kinect. A huge amount of Kinect titles have also hit the street in the last couple of weeks as well so the consumers believe Kinect is supported.
Finally look at the Holiday Console Hardware Special Deal thread. MS is already starting with the promotions. Nearly every major retailer has a $50 credit on 360 purchase this week. Look for this all November and December.
Its libraries that sell systems not a single game.