PC ports direct to Xbox a lot easier and earlier titles for PS3 had issues from learning how to port the titles. That's gotten a lot better. Because Xbox has been rabidly seeking first releases, it's become a beta test for the PS3 final versions. For me, that's good. I can buy a Xbox version to play until the refined and polished PS3 version comes out. =)
Either way, owning both systems gives you the best of both worlds.
PS3 resurgance by GOW3 - Check! Mass Effect for PS3 - Check! Diablo 3 for consoles? I say "For sure"!