Some other site had a good essay on why releasing just before the holiday is NOT a good idea.
Its because MOST of the game buying public does NOT follow news sites like this, so if the game comes out in december most kiddies wont know about it in time to get thier parents to buy it. But if it comes out months before hand, and other poeple buy it first, they start spreading the word about how it is the MUST HAVE GAME, then the kids have enough time to whine at their parents and the parents will then have time to buy it.