I personally like downloadable content.
I think people are going to see that "future episodes exclusive" balloon and not know what it even means or care. Despite the price, low sales and no games PS3 has more positive buzz. The average consumer doesn't know about MS customer service, only that Al Roker said their were recalls and that an xbox killed a baby (which probably isn't even true, but it went to court and had a 30 sec sound byte). 'Last generation console buyers' surveys keep showing that people want a PS3 but feel that it is too expensive or that there are no games.
360 has games so their is already significant motivation for gamers to buy it, GTA wouldn't have as much of an impact. IMO GTAIV would have been one of those games that got people to stop waiting and buy one already. A lot of people waiting for it on 360 may have bought one for Crackdown, Saints Row (both games considered to be for people who couldn't wait for GTA), Gears of War, Lost Planet, the slew of Tom Clancy games that are better or currenty exclusive for 360 (I partially know because I owned Vegas on both). And the 360 is cheaper so you need less motivation.
I am not even a MS fan, and I can give them all that credit. If you look at my post History I am pretty biased (but respectful) against 360. Because 360 is strong it doesn't need GTA as much.
I would cite regulation, but I know you will simply ignore it.
