Hi,
A possibly related discussion; we've been wondering if we can make the OS image read-only (mounting it that way, or via selinux).
Then have /tmp and probably /var in RAM (or wiped on boot), and have home directories and server/app data such as web pages to be served on network mounts.
This allows you to maintain the OS image in a central location and the homedirs and server/app data in central locations, and have a single network-wide master copy of all important state.
Any filesystem rearrangement probably impacts this plan (some rearrangement may be needed for this plan).
Havoc