On Monday, January 9th, Greg Kroah-Hartman published an update on the status of the longterm/stable kernel trees that he's maintaining. It's worth a notice if you're interested in the state of the longterm kernels.
We last checked in on the stable and longterm kernel trees at the very end of 2010 when Kroah-Hartman announced some changes to the changes to the stable kernel release procedure. Things seem to have been going pretty well, but as time passes it's time to phase out a few trees and bring in the new.
Right now, Kroah-Hartman is maintaining several kernels (x is the minor revision):
The 3.0.x tree is the new longterm kernel release. According to Kroah-Hartman it will be seeing updates for "2 years at the minimum by me."
Steven Rostedt, who works on the real-time Linux kernels, says that he plans on maintaining 3.0.x-rtx releases for two years as well.
The 2.6.32 release came out in December of 2009. Kroah-Hartman says that he plans to maintain that one for "another month or so" and then he's finished with that one. However, it's likely to be picked up by another maintainer. The Ubuntu folks plan on maintaining the 2.6.32 series through 2015, and Kroah-Hartman says that he has a maintainer in mind to take it over.
The 3.2.x kernel will be maintained by Kroah-Hartman only until 3.3 is released. The 3.1.x kernel is going to see one or two more releases, says Kroah-Hartman, then it's also being phased out. It's interesting to note, the Ubuntu LTS coming up (12.04) looks to be using the 3.2 Linux kernel, so there should be at least one distro maintaining that one longer.
It's worth noting that Kroah-Hartman isn't the only kernel maintainer looking after longterm versions. Paul Gortmaker is looking after the 2.6.34-longterm kernel, and Andi Kleen is taking care of the 2.6.35 kernel.
Finally, there's the Long Term Support Initiative (LTSI) for embedded systems, which will also be maintaining trees for two to three years.