looks like microsoft couldn't keep the pack to themselves. maybe the recent PS3 slim announcement and price drop made rockstar realize it will do good on the PS3 platform.
The funny thing is, some people say microsoft paid rockstar to make all the expansions exclusive. if this is true, then so be it. i for one am happy for it coming, that is if it is coming.
This isn't a new game, it's just a new expansion, a new story to go along with GTA IV. if you didn't like GTA IV, then chances are you won't like any of it's expansion packs either.