I have been in California visiting some customers this week and a few of our customers are looking at or testing things with VMware and filers. Keeping virtual machine copies of your desktops and servers makes a lot of sense on filers. If you have a machine problem load up another server with the VM copy. Also, it makes the testing of various versions of software on different operating systems a lot easier. Just keep VM copies of the software on your filer and download them to the desktop or server as you need them.
It might make keeping your remote users on the network a lot easier also, simply have them run a VM that has the exact settings for your VPN.