Oh please, it's not even slightly amusing. Two companies announce that they are going to embrace cross-platform development and everyone starts acting like it's the end of the line for PC gaming.
Doom 3, Quake 4 has been released cross-platform, same goes for the UT series, it was previously cut down for the consoles though.
Who cares? Playing on consoles only diminishes the experience.
Even with Quake Wars: the maximum number of players is lower by a third for the console versions.
Also, for people who are saying that they'd ditch PCs if Kb/M controls would be available for consoles: it is just stupid. Better controls are just one aspect of PC gaming-but there are many many more. I'll switch over to consoles only when there'll be an upgradable, open console. And even then, the proprietary nature of those still will repulse me.