It looks as if Microsoft is to break with recent tradition and release the new Halo closer to Christmas than it ever has previously.
The Verge claims to have word from a reliable source” that Microsoft has internally set November 6th as the release date for Halo 4. Furthermore, it predicts that the date will be announced today.
November 6th would certainly fit in with Microsoft's recent reveal that the game would release at Christmas.
It is, however, a deviation from its recent Halo strategy. The last three releases in the series – Halo 3, Halo 3 ODST and Halo Reach all released in September.
You have to go all the way back to Halo: Combat Evolved and Halo 2 in 2001 and 2004 to find the last time a major Halo release hit retail in November.