I've always liked SELinux. Well, at least ever since they fixed their security policies. When RedHat first introduced SELinux in Fedora, it broke several things all over the system. All I-can't-get-this-to-work-on-Fedora-Core-2 queries on all forums and mailing lists, were answered with the "turn-off-SELinux".
I've written two articles on SELinux, one in January 2005 and the other in December 2006. Between the two years, and 4 Fedora releases, a lot had changed. From a little-tested policy that worked best in a controlled, restricted environment but not at all well on a regular desktop, SELinux policies have evolved. And how! SELinux under FC6 has a new Multi-Category Security policy, there are several graphical and command-line tools for analyzing policy and AVC audit messages, and the SELinux Troubleshooter that detects denials and suggests fixes.
Now it looks like companies are starting to notice and helping users utilize the full potential of SELinux. Hannes Kuehnemund from SAP recently wrote on his blog that several SAP customers "are already asking about SAP and SELinux". He goes on to explain in detail how to implement an security policy on a SAP system running on RedHat Enterprise Linux.