I've got all of my configuration in version control and handy script to create new modules from templates. I'm already pushing out OS specific configurations as well as OS version specific stuff. Augeas is AMAZING. I don't know how I never found/saw it before.
We're also pushing out Splunk (Cox is a huge Splunk customer) across the board. I'm still undecided about its value but I haven't really looked at it since it first came out. It just seemed, at the time, like a huge overhead for a problem that was already tackled (syslogging).
My next step is deciding how to integrate everything into my Kickstart scripts. There's a TON of options out there. I'm really trying to avoid setting up Cobbler but I might be at the end of what can be done with Kickstart already.
I'm still frustrated with managing current versions of Ruby and gems with RPM but gem2rpm has made some of that easier. I'm not responsible for the Solaris boxen so I have no idea how those guys plan on managing those bad boys.