I think you have the main points but wrong order. MS knows it is coming from behind (if you'll pardon the phrase) both in terms of brand recognition and first party support. Therefore it's clearly:
1 - using timed exclusives as a denial of service tactic to try and force people towards the 360 as many gamers simply can't wait for big games. It's fair in business but not something I personally condone. Basically, it's like a sportsman holding the back of the shirt of an opponent to keep them close
2 - using timed exclusives to get more attention for 360 and have it seen as the console with more titles/content. They know than many gamers, particularly the teenage/young adult males will ignore the fact the title isn't really exclusive when it releases on PS3 in the end
3 - a variation of 1 but I think they also used this a lot to try and slow up the PS3 in Japan particularly to give them more room to grow in the region. Again, fair play in business, but I'd personally prevent this as a could as I don't agree with the practice.
As the core of this approach is acutally negative to the consumer, which is my main focus for business regulation, I don't like it. If MS want to be successful they shouldn't do it by focusing on tripping up the competition but being better themselves. Instead of 30 day DLC timed exclusives, 12 month exclusives, etc. I think all of that money should go to IP instead. They can commission true exclusives with third party developers, get more Mass Effects, Gears, etc. on the console instead.
Even for 360 owners I therefore don't see this as a good practice. Sure, the really nutjob fans will see it as great, but in the end you're not really getting anything truly exclusive just first play vs true exclusives like Alan Wake. I would hope most 360 owners would rather have 3 exclusive new IPs heading to the 360 rather than playing a multiplatform title first.
I'm not sure how much MS will focus on this now though, as once the game was up first time around, most people now assume it's just a timed exclusive now and assume the title or DLC will hit PS3 anyway, which seriously undermines the practice.
Try to be reasonable... its easier than you think...
