funny thing is we had this issue yesterday. We had a host just fail on us, thus leaving a 140 VM's in a disconnect status. As far as VDM was concered the pool was in tact because even though the VM's were disconnected, the were still registerd in VC, howerver once we disconnected the ESX host, VDM immediatly started to deploy new VM's. I don't think this is a bug, this is the way VDM should act if you have your desktop pools constantly enabled. It's kind of a catch 22.
We brought this up on our Friday morning call with VMware Engineers.
EDIT: We did not use HA, but now have decided to go with it. The key if using HA is to have the VM's remain powered on, because if they power off, VDM will start re-creating them at the same time HA is bringing them up on other hosts in the cluster.... Talk about a mess!!