Huh? I don't see any need for SE to share marketing with Sony on FFXIII as the impetus is on Microsoft to let their userbase know the game is actually coming out on the Xbox 360. Of the people who care, they all know its already coming out on the PS3 so they just need to know when to buy the game.
The same kinda applies to GTA IV as well. But the thing is, the DLC was a payment for a loan and a likely profitable one for Microsoft as well because it reinforced the strength of digital delivery on their platform.
The same applies for MGS: Rising as with GTA IV and FFXIII...
Tease.