I emailed John Carmack of iD Software to see whether or not they intended to release both Rage and Doom 4 on Linux. He responded:
It isn't a launch platform for us, but an executable may still show up.
Anyways, I figured that some of you may have been interested in this so I figured I'd post this here. For those who didn't see the new E3 trailer for Rage, you can view that here:
Also according to John Carmack (from a small interview), as good as Rage looks, while Doom 4 runs on the same engine, it is suppose to look a lot better. Details on that can be found here:
EA is not iD Software's publisher so I'm not sure if that little fact will hinder any Linux port developments.