Ha....ha. Id like to say I told you so.
Having a ton of exclusives every year with therefore thin spread marketing per game will lead to sales of each game not giving a proper return on investment. Without proper awareness, blockbusters will be rare and therefore will fade in the memories of the general gaming public within a year.
Thats why MS releases a few exclusives and markets the crap out of them, while releasing new games on lower-risk avenues like XBLA where it doesnt really matter if they flop or not.