In early September 2004, Red Hat released Update 3 to Red Hat Enterprise Linux. This includes all package updates since Update 2 and many more. Aside from important security fixes are improvements in Unicode handling and drivers for newer hardware. There are also some nice new features such as the LAuS auditing subsystem and the ExecShield kernel security feature. Full release notes are available. As always, updates and ISO CD images are available via Red Hat Network.
In our experience so far, this update has been completely compatible and has installed flawlessly, including the reboot to load the new kernel. We generally recommend Red Hat Enterprise Linux for our clients' production servers and are pleased with the ongoing improvements and very long support lifespan. Havoc Pennington explained in detail the work that goes on behind the scenes to make Red Hat Enterprise Linux in a recent blog entry.
We don't want to detract in any way from other excellent operating systems we use, such as OpenBSD, Debian GNU/Linux, and Fedora. But for managing a large number of multi-purpose production servers, we've found Red Hat Enterprise Linux to be a good fit.