Can anyone give me one reason why konami shouldnt release this on the 360 as well?

Konami -> MGS4 = Capcom -> RE4

Looks like Konami didn't learn the lesson from Capcom's mistake with RE4.

Capcom announced RE4 would be ported to PS2 before the GC version came out, thus seriously lowering the potential GC sales (people waiting for the PS2 version rather than buy a GC for it) and lowering the potential PS2 sales because by the time it came out on PS2 it was old news.

They want to lose money?

If Konami truly is bring MGS4 to the 360, the writing is on the wall for the PS3. It will be like when Square left Nintendo and went to Sony. It created a snowball effect and soon Enix left Nintendo as well. If Konami goes, Square-Enix can't be too far behind. The Last Remnant may not be the only Square Enix title headed to the 360 in the near future.

The leading theories seem to be that they're loyal to Sony due to their "good history", and that they want to develop on the PS3 because the yet unnoticable power difference between it and the Xbox 360 is going to make the game vastly superior (enough that even a remake after a year would ruin it?).

Sounds pretty far-fetched to me too, but cognitive dissonance always finds a way. 

MGS 1&2 were ported to every system known to man. MGS3 was the only Sony exclusive.

I'd consider this to be a timed exclusive at best. Its coming out for the PS3 in less than 6 months and there has been no announcement about even development starting for other consoles.

Porting to the 360 would take another year at least, so this will at worst be a timed exclusive. This "news" is brought up every week it seems, nothing changes.

Does anyone else have the feeling that because the PS3 is doing so bad, the 360 is the main console which takes advantage of it ? Because in my opinion the success of the Wii in Japan is one of the main reasons why Japanese developers are questionning the PS3

You don't read so well do you?

There was no implication of the PS3 version of those games being canceled, but was a statement that multiplatform games in general could be canceled. We have already started hearing rumors of games (like Katamari) being canceled on the PS3 so the statement is reasonably valid.

@Uma: Yeah my feeling the same, the 360 is getting the titles as well, which were mainly exclusive for Playstation, like Virtua Fighter 5 for instance... But on the other hand, the PS3 also gets the 360 titles such as Oblivion, Eternal Sonata, Enchanted Arms for instance. Only because the WII hasn't got the same power, well and of course because of the casual image of the console. For that I really doom the WII at times.

So the possibility of MGS4 going to the 360 increases. Is this is a surprise to any but the most diehard Sony fanboy?

Here's a thought, does the possibility of MGS4 going to the 360 increase the odds of FFXIII porting as well? Does either company want to be the last 3rd party with a major exclusive on the PS3? The two together may be able to push enough systems to be profitable but I doubt either Square or Konami are arrogant enough to think their game alone will push enough $500 systems to matter.

Anyways, the FFXIII multiplat watch just got more interesting.