Prediction: This year will be the defining year for the console war with regard to the HD consoles. Sales this year will be representative, percentage-wise, of sales for the rest of the generation. If Sony outsells the 360 11 million to 10 million, it will outsell it by 10% the rest of the gen (that was just an example).
This will be extremely interesting, especially with GTAIV. Both sides KNOW that game is basically the turning point that everyone is watching, and it will be very fun to see what each side will do by April, and how they will counter one another.