RE: Domain join and vSphere vCenter 4 with 2008 Datacenter Edition x64 SP2 guest, KMS (default) key.
I've tried the suggestions in this thread with no luck on the domain join working. In fact, looking at the sysprep logs, there's no indication whatsoever that any domain join operation was run, requested, or otherwise by the VMware customization process.
It's a brand new from-scratch template, so while I could create a new one that doens't seem likely to be the issue (plus, we can't really count that as 'fixing' the issue now can we?
The VMware side customization logs don't reference any domain joining actions, and they complete with no errors visible in the log or in the guest's event view in vCenter.