Im thinking around 6.5 million, I have no stats to back it up but looking at past halos 6.5 million for 9 weeks of sale is amazing and would still be higher than reach. Plus there are alot of halos already on the 360 so even 6.5 in 9 weeks is being generous.
Past Halos were all released in September, so you can't really compare them to Halo 4. November is a completely different sales climate
Thats true but It doesn't play in its favor with COD releasing around the same time.