We've known that id Tech 5 is likely to have Linux support going back several years now, just as the earlier id Software engines and games have played well with Linux. id Software cares about Linux support for ensuring their engine is portable, id Tech engines have traditionally used an OpenGL renderer without much middle-ware, and John Carmack is also fond of the platform. id Software has also open-sourced their engines once their useful market life has ended. But back in August we learned that Rage may not be coming to Linux soon.
The Linux client port of Rage was not a high priority, but basically at the bottom of the company's TODO list. The latest I've now heard is that at "some point in 2012" is when we will likely see the public release of a Rage Linux client. It sounds like there's a fair amount of work left, but at least it should come, unlike the big Unreal Tournament 3 Linux mess.
At least there's still the Doom 3 source code to look forward to this calendar year. This also gives Mesa / Gallium3D graphics driver developers more time to reach better OpenGL 3/4 compliance for the id Tech 5 engine and to try to deliver an acceptable level of graphics performance compared to the proprietary AMD / NVIDIA drivers. It's unlikely though that even in 2012 we can enjoy id Tech 5 / Rage with decent settings and performance from the open-source Linux drivers.
For Linux gamers not familiar with Rage, below is a launch video released yesterday.