You understand that if sony finds out and investigates Konami is going to be killed?

 So its a fact that MGS4 wont move consoles outside of Japan? I hate when people say their opinions are facts. No its not a fact, not even close. 

Sony, Konami, and even Microsoft believe it will move consoles, which is why exclusivity is so important. It MAY come to the 360 a year later depending on PS3 install base and attach rate.  But it doesnt need to, for all we know the PS3 may have more consoles WW than the 360, and its attach rates for the lastest huge titles (Assassins Creed and Call of Duty4) have been very similar. 

@starcraft

MGS4 will sell at the least 5M copies on the ps3, every hardcore ps3 fanboy will get it which is 70% of the install base.

Do you understand that Sony has nothing to do with this game, except that he is on PS3 ?

MGS sales have been declining in the last years, and the last one sold only 1M copies on a platform with almost 4X the userbase. Do you really think that 5M is acheivable ?

 Leo is absolutely right about this.  Witness how 70% of PS3 owners picked up the highly established, critically acclaimed Rachet and Clank....er.....oh.....

achievable in time, IMO- YES. This game is different from the previous ones since it will exist on a console with less games at the time of its release than the previous MGS's had. It will become the top selling MGS game IMO

@Leo: Not even Halo has a 70% attach rate. I think it's bordering on 50%(?).

OT: If MGS4 did come to the 360 a year or so later, it would be like Resident Evil 4. It was hyped to be this amazing saviour of the languishing 'Cube. Nintendo had absolutely guaranteed exclusivity with Capcom. It wasn't, even though it sold many millions of copies. They ported it to the PS2 about 8 months later, and while it didn't sell as many copies as the 'Cube version, it sold several million and justified its' appearance on another console.

mgs4 if it sells a million copies on the ps3... probably won't make much money for konami- it cost ~25 million to make... they'll break even somewhere Around a million or so

they'd be foolish not to do the port.. almost double the potential userbase for another 2-3 million in Cost to do the port.

if it sells a million on the 360, Most of the money would be profit...

 There is an obvious answer to that question.

But I really hate rumors myself, if its true its not going to change between now and when they announce it.  I can wait.