I’ve just read a forum post where a VMware expert (a real one) has been reporting issues with the recent vCenter 4 and ESX 4 updates. The latter one is scary; it can kill a host and lose some of your VM’s. The problem happens on ESX if you manage the host using 3rd party agents. VMware is advising that you remove the agents before an upgrade. Another article is posted about the vCenter issue.
This is a bad play by VMware. They’ve built up a loyal customer base but dodgy releases like this will get people interested in the possibilities of using VMM 2008 R2 to V2V migrate their VM’s onto a Hyper-V platform.
The expert in question has been advising people to stay clear of new VMware releases; let someone else test them on their own production environment.