Do what I do, never even think about it and you won't be dissapointed. But there's light in the tunnel - PS3 Vs PC and XBOX Vs PC, the PC being the "neutral" ground, seeing as it's not a console.
Yeah, never really get why people all flame how one or the other console is better when both have awesome sauce in large amounts... erm... Sony has a bit more of course (not only is it true, but I hope it gets the mods off my back... )... I'm console-less now. So it's portable gaming.
I thought of this before too. Though, this could only be done with a 3rd party game using their own game servers and people could not add others as friends directly through PSN or XBL since they might not even be on the same service. Maybe someday some 3rd party company will make a universal online game with PSN, XBL and NWC, but I don't think any of the gaming console companies will actually posts events about it or directly sponsor it.
Get your Portable ID!