There is one already and it's official.
I don't really care much for the new id Software, they haven't really made anything good lately and Doom 3 was a pile of monster closets. The sad part will be classic franchises getting dragged out from their well deserved resting places only to be molested and turned into something unnatural like a person who stares straight into your soul while you feed them the conversation pie.
I doubt that this will affect Rage too much, if anything it will get them more funding.
EDIT: Props to them for all their Linux stuff, I'm sure Beth will kill that ASAP.
In the announcement it was made pretty clear that id will continue to operate independently, so I doubt Mac and Linux users will have anything to fear.
From a business stand point it does sound like a big money sink. Guess we'll see. Maybe Obsidian will get to use some of their awesome tech for future Beth-Obs projects?