1. Virtualization
Virtualization would allow us to avoid having to dedicate an entire physical machine to the KDC/AFS server. It would also allow us to snapshot and migrate VM instances between machines in the future if needed. OpenVZ at least allows VM images to be suspended, migrated to another physical machine, and resumed with no apparant interuption to userspace (aside from network connections and such potentially timing out). This kind of flexibility would make future expansion a lot less painful.