One thing that drives management nuts here is the fact that VMs can move between physical machines. They like to know EXACTLY where VM X lives all the time. While I realize that documentation can go a long way, I rarely move all VMs back to the same ESX host following hardware maintenance.
It might be nice to be able to create groups of VMs that you could manage as a group. For example, if I had to move all of the VMs off of esx02 in order to do a hardware upgrade, I generally spread the VMs among the other servers in the farm while I upgrade the host. When it's time to bring esx02 back online, It would be nice to grab a group and toss it back onto esx02 to put everything back the way it was -- kind of like a bunch of VMotions in serial or something.
Thanks for listening