I haven't done my upgrade yet; I have an important production database server to virtualize this weekend, so I won't be trying to upgrade until next week.
I used to have my vCenter as a VM, but we had weird problems, so I migrated it to a physical machine, and the problems went away. Don't know if they were related, or if I had just screwed up my original install as a VM, but now my vCenter is a physical box. And the SQL 2008 server is also a physical box (as it also hosts other databases for other apps).
As for the 3rd party plugin (Emulex OneCommand), I uninstalled it, on advice of Emulex Tech Support (who are very helpful, BTW, even on support via email). So now I have a "clean" installation, to try upgrading.
I will report back, when I have more results.
Have you called VMware about your problems?