If you are tracking the Linux kernel development (which is not a bad idea for Linux system administrators), then checkout the Linux Kernel Weather Forecast from the Linux Foundation. There is also the blog which summarizes the main changes to the Linux kernel, as well as a RSS feed of the same.
The Linux Kernel Weather Forecast tracks changes that are coming up, and patches that may be added to the kernel soon. It tracks the current release versions, as well as important related information. The blog contains updates, but the main page lists the current status of everything. There is also a RSS feed of the changes made to the main page.
What’s not to like? One stop information about what’s happening with the Linux kernel – woohoo!
PS: OpenSolaris and the BSDs should have something like this!