According to a Rockstar dev: "They're both identical"

Basically they made sacrifices to allow the game to fit on DVD and they had some problems changing their engine to support the PS3's SPEs (which always take time and effort when dealing with legacy engines), but that's been taken care off to make both version identical.

""misteromar mk4 said:
I say M$ will also be getting the superoir GTA4 version in terms of graphics, frame rate etc.""

==> just your first this sentence is BS
we have seen nothing from the PS3 version ...

Actually I doubt advertising the hell out of it will affect much of anything.

I think existing 360/PS3 owners will go with their version. Unless the extra content is a serious amount of extra content only a few PS3 owners (and very big GTA fans) would buy a 360 just to get the extra stuff.

This is all about the fence sitters... but I don't think this will actually shift too many fence sitters one way or the other in the US. I mean how many people can there be who haven't bought a 360 already (with Halo 3, etc) out who will buy one because of GTA IV?

Likewise for PS3 - are there people in US who don't have a PS3 nor a 360 who would buy a PS3 on the basis of this game (given they can buy the more popular 360 console?)

I could of course be wrong but I expect it to be more like COD4 or AC- a very big seller in terms of units on both platforms, but only drive a modest spike in consoles for both (in the US).

Outside US is where the fun begins with regard to fence sitters. There is much more of a chance I believe of GTA driving actual console sales outside US I believe - but for whom is much harder to call IMO. PS3 seems to have more momentum at the moment, but 360 will have the extra content card. Of course it will likely be more associated with Plystation and PS3 does deliver BR, etc. which I believe has more impact on buyers outside the US right now.

Oh please, of course making a PS3 version of GTA IV was worthwhile. It will sell 2 million copies easily, and is likely to break 3 million+ by the end of the year.

There's no way that isn't worth it.  

Just to let you know, Blimblim post on NeoGaf, yes, but mainly, he has one of the best sites in the world for HD trailers, http://www.gamersyde.com/

I wonder if Microsoft will pull a Sony....

You know market the game as exclusive thought it's not. Sony has done that with a few games on their viral campaign to push the PS3 here in the US.

Microsoft should do the same thing.

@ XGamer0611

I think GTA fans are well aware of both versions.

They could always do this: 

GTA IV: 360 Exclusive Content!!!!

or

GTA IV:

360 Exclusive

content

 In that case, why even market it at all? 

I know, I'm just being facetious.