Heh, i don't see how this ruthless, the game itself isn't even exclusive. Had they made the game exclusive then yeah i could see how MS simply decided to say "f it" and just storm in with the cash and buy the damn exclusive.
This harmless when compared to when these companies get exclusives, like MGS4 or Splinter cell conviction.
Sony had the whole marketing gig locked down for COD4 and AC, don't see how it's any different now, seems to me that MS decided to go after the big fish.
Even with Sony doing that COD4 sold between 2|3:1.
And ram talks about Europe, well, doesn't mean MS is just gonna quit, the PS was supposed to be leading in the U.S too, so it seems to me that it's always worth a try. Obviously MS did the wrong decision in going after Japan when they should've gone after Europe, but at least they were able to grab a big market here, the UK.