What fueled the rumor the second time around wasn't the stamp but an interview that spong had with ken levine. When asked about the PS3 version he replied:

"If I talk about anything outside of the Xbox 360 version, my corporate overlords will spank me. We love the 360, we love working on it and we’re not talking about any other versions right now."

Personally I am getting bioshock on the 360 but that is a pretty sly response wouldn't you admit. Besides this whole rumor started of because magazine scan

http://www.maxconsole.net/content_img/biops3.jpg and threespeech entry
http://threespeech.com/blog/?p=377

Honestly..... permission is asked to post pictures up so obviously at one point in time even 2k had plans to bring this to the PS3 and dammit threespeech being wrong about Sony related products is incredibly odd. So there is actually more substance to this rumor than the MGS4 one.

I am not saying that a port would never happen. But it isn't likely. I am going to assume it falls in line why MGS3 wasn't released on the xbox even though part 2 was. Kojima himself doesn't like to make ports. He doesn't seem to be a fan of the xbox, chances are MGS4 as a port would have to see the light of day due to another team in konami's fold and I am guessing no more than a year and a half later at that.

EDIT: here is spong interview  http://spong.com/detail/editorial.jsp?eid=10109632&cid=&tid=&pid=&plid=&page=4&cb=965

And gebx the rating of enchanted arms is besides the fact but good job of finding the worst one

http://xbox360.ign.com/articles/729/729488p1.html ign gave it a 7.6 and it recieved 80% and more on sites like RPG fan Xboxaddict and Planet Xbox.

The high rating led me to try it out on my 360. 

Bioshock will not come to the PS3, why? Because it is a AAA titles and will sell for profit
MGS4 might come to the 360, why? Because no one knows how good the games is and it might not break even.

 lol

Right, games never start out being developed on one multiple systems only to be cancelled when they realize thats not profitable, or some console maker hands them a wad of cash. For example, MGS started development as a title for all systems - PC, PSX, N64 and Saturn. Funny how that turned out...

But give me a fucking break. Years ago the producer said the game would be exclusive to PS3, yet this is sounder evidence than the head of Konami failing to outright deny a port recently?

Can't you see how hypocritical it is for someone who was so adament that MGS4 is exclusive to so quickly claim that Bioshock may hit his platform of choice?

So now we have to games with an only for sticker.... RE4 above in my first post (and here), and Enchanted Arms.

2K reps just contacted us to let us know BioShock is exclusive to Xbox360 and PC Games for Windows.

I think this is just about as good a Kojima saying MGS4 is exclusive to the PS3.

http://kotaku.com/gaming/bioshock/bioshock-a-lock-for-ps3-250434.php

 Some months ago :

Capcom confirmed that DMC 4 will be exclusive to PS3.

I am not trying to say it is coming out for PS3, I am saying companies lie, even on the box art (see my above post) because they get paid to put that sticker on their.

 I think that's what sieanr is trying to say. If 2k said that the game is for PC and 360 only than that's as good as Kojima saying MGS4 is for PS3 only.

 Yeah sorry,  I wanted to edit my post but you already quoted my post X_X.