Original poster, flawless analysis (I love it).
However, that is if you're taking Rockstar's GTA announcement at face value. You see, just recently Sony said out of the blue that they would be the winner of this generation easily be March 2008 - right around GTA's release date. I think it's pretty clear Sony has a major, major price cut in plan, and with that they believe the Sony Playstation brand name will be good enough to sell the machine.
And that's why GTA is being released around that time, to capitalise on the much larger PS3 fanbase.







