If you’re a Dell sort of person you’ll be happy to know that version 5.4.0 of the Dell OpenManage Server Update Utility DVD works under VMware ESX 3.5. Older versions didn’t work, which made firmware management more difficult.
I don’t currently run the OpenManage suite of tools. Instead, I copy the SUU DVD contents to an NFS share, and I have a shell script which handles the mounting & unmounting, and updating my servers. I’m glad that the whole process works on ESX now, too.
 I might, in the future, especially as things like ESX 3i remove the OS.