I bet if Mirror's Edge or Dead Space was 360 or PS3 exclusive it would have done a lot better. Total sales may have been down a little bit, but I'm sure it would have gotten much more support from whichever console company it was exclusive to, the fanboys of the respective console would have gotten behind it and the hype would have been much greater, the design would have been more focused for the specific console and it would have gotten a better brand name equity for future titles. Instead it's sales were pretty decent but no one really gives a shit about those games anymore, they got lost in the mix.

The more 3rd party developers decide to go less and less with exclusives I think the more appealing it becomes for 3rd party developers to go exclusive. Obviously if a game reaches the status of GTA or Resident Evil or Call Of Duty it's best to go with a multiplat format because the games will sell themselves and the bigger userbase the better. But for newer IP's and less established franchises, going exclusive could give the brand equity boost and the development focus that the game needs in order to reach the status of those top selling games.

I was about to make a few arguments about why the GODII release was a different situation seeing as it was 7 years into the PS2 life cycle which had every game imaginable on it already and newer consoles already started coming out and Sony started moving it's marketing resources to the PS3 and gamers started becoming less urgent in buying games, but then I checked it's numbers and it sold over 542,000 first week in America alone. No European numbers are posted, I would assume that those numbers would be about par with America and including Japanese sales, it's about 1 million the first week. So... I don't know if i believe you that it didn't break 1 million the first week.