As of right now, it’s all rumor.
Here’s a prediction; we’ll see the Halo series make it’s way over to the PS3 by the end of next year (if the split happens). We’ll see all three games on one Blu-ray disc for the PS3 in time for Christmas 2008.
And, I’m betting that Bungie pulled an Apple and developed the PS3 version of Halo 3 alongside the XBOX 360 version in a secret basement full of roaches.
I can see all the Microsoft whiners having a fit over this tidbit.