If somehow Blizzard decided to put it on consoles, I doubt the console and PC versions would be playable together...it'd have to change the entire battle.net system because we all know the consoles can't adapt.
It'd be cool but I don't see it happening, mainly because Blizzard won't want to. Valve's been doing it lately with the Orange Box and Left 4 Dead, but they're A) getting other developers to do the porting, B) not really updating the games (because it's a painful, stupid process that takes weeks), and C) ignoring the PS3 because it's a bitch to develop for and not worth it.
LEFT4DEAD411.COM
Bet with disolitude: Left4Dead will have a higher Metacritic rating than Project Origin, 3 months after the second game's release. (hasn't been 3 months but it looks like I won :-p )