Just to add to this a little for any of you that have ever wondered what the difference between the 2.4 and 2.5 tree is:
All it is, is the difference between the stable kernel and the development kernel. The odd number (the "5" in 2.5) signifies a development kernel. When 2.5 becomes stable, it will turn into the 2.6 tree, which will be considered the new stable tree. (Whether or not it is a stable kernel or not is a different story).
I know some people are confused as to why the distro's don't include 2.5 as it's the "newest" kernel, but that's the reason. It's just for testing new features, etc.