If
it was up to Epic President Mike Capps, he'd put the
Gears of War trilogy on the PlayStation 3. As a game developer, who doesn't want their product on as many consoles as possible in order to grab the largest audience. Epic's no different.
But, make no bones about it. There are no regrets with what they are doing with Microsoft. Gears has been a huge hit for both Epic and Microsoft and the relationship they have have benefited each other greatly.
That said, Epic does own the Gears IP so they do have a possibility of doing something in that universe for the PlayStation 3 if they want to. It might not be a Gears game, but it could be an off shoot of some sort. Or, they could some day throw the entire trilogy onto Sony's game console.
I'd love to have 2 and 3 appear on the PC though after having a good time playing the first one on the computer.