From Kotaku:

There have been rumors of Sony buying up R* in the past, and given R*'s history with the company (GTA, Bully, etc.), and current exclusivity deals (L.A Noire, unannounced new IP for ps3), I could see Sony picking them up in the future, especially if the ps3 is still in a dismal 3rd place come 2009. Sony also has a history of buying out studios (Eveolution Studios being the most recent), or contracting them out as 2nd party (Ninja Theory, Media Molecule).  However, Sony would probably buy out R* if they did anything, as they usually only make small, fledgling studios 2nd party, providing thm with support and publishing their games.

I could see Microsoft possibly contracting them out as 2nd party, but definitely not making them 1st party. MS seems to favor signing exclusivity contracts with independent studios or taking up the role as publisher rather then buying the studio outright. They've been publishing games for Bizarre Studios, BioWare, and the like for years, yet they don't seem to mind letting them get bought up by other, larger developers. They even let Bungie go, who knows why.

Sony couldn't afford the GTA license alone - that would be worth up to 1bn, just on its own. Throw in the studio, and everything else - and MS have much more money to burn than Sony.

This isn't even possible until mid 2009, and even then the price will be enormous if they do decide to jettison themselves.

I'd say we wait until Christmas 2008 before we even begin discussing such things.  

Sure it may cost sony as much as a billion buks, but they would make a huge amount of profit afterwards. Could you imagine if they cancel GTA 4 for the X360? And they announce it ps3 exclusive? Not onl will they mkae millions, but ps3 will get a large boost in sales. Same goes for microsoft if they buy rockstar.

"""Could you imagine if they cancel GTA 4 for the X360? And they announce it ps3 exclusive?"""

==> sure, it would be awesome for the PS3
but
seriously,

Could you imagine that Microsoft will just sit down and look sony making their move ? ? ?

If either party bought out R* it would be a massive coup. They could both afford it in theory, but if there was a bidding war the cost would be colossal. I can't see MS going for it, or Sony for that matter, but it would be interesting to see how much they'd be willing to pay if they did.
Does anyone know how much Take 2 bought them out for?

 as Bodhesatva said this isn't even possible until mid 2009 so Sony will not be able to cancel GTA 4 for the xbox 360.  the next two R* releases are already ps3 exclusive so Sony has little to gain from buying R* in the short term.

True, it won't happen until mid 2009, but - based on the fact MS ponied up $50M for exclusive content, I don't think it's a stretch for them to buy R* and just freeze Sony out of the loop completely. No one - I mean no one - does open sandbox like R*. And when MS ignored R*'s request to make GTA exclusive on the original Xbox, MS learned not to make a mistake like that twice. And Saint's Row was a good holdover until we get GTA, but still - it wasn't GTA. I feel for the Sony PS3 owners ...

Bottom line, if this happens, and R* can have the freedoms it wants with M$, I'd put my money on MS snapping it up. Sony can not match M$'s sheer desire to whip the competition.

""" And when MS ignored R*'s request to make GTA exclusive on the original Xbox"""

==> seriously ?

but why did R* want to make their game exclusive to Xbox ?
the sales were good in NA, but were nothing in PAL.
The multiplateform PS2/Xbox was great for R* ...

If Sony can win this war, it's not with money. Long gone are the days when Sony was the richest competitor in the gaming world.