There's really nothing like some new hardware to get the blood pumping. I've been converting my sad, old, NFS + LDAP serving cluster over to a fancy new Kerberos + AFS + LDAP + XEN environment. Virtualization is truly awesome, being able to create and reboot hosts at will without concern for the possibility of a late-night drive to the datacenter is so nice.
Probably the nicest part is that as I go to set up a new system, I can do a complete trial-run, documenting my changes. Get it working, then repeat the process with another vhost following my documentation to verify that the process is correct. Having so many potential options at my fingertips is a bit dizzying.
The thing that made all this possible was finally figuring out how to get around the damn kernel panic I was seeing using the ubuntu xen packages. Unfortunately it has to do with their forward-ported 2.6.24 xen kernel. If you go and get the official xen distribution and install that, building the kernel from source (which is a bit messy if you try to adapt the ubuntu kernel config), things work much smoother.
The kernel is a little older, and you lose out on some of the nicer drivers to have in the most recent kernels, but having a stable xen host is worth it. Especially with a server where you really only need disk + network drivers.