I've been doing allot of research on VSS VMWare and why it's necessary to purchase 3rd party solutions to get VSS "APPLICATION" aware backups.
http://www.backupcentral.com/content/view/287/47
VMWare has been completly SILENT on this issue. One of the only things stoping VDR from being a solid backup solution for most small business is the lack of VSS application level queiscing. If microsoft Hyper-V can do it, so can vmware.
that or atleast be honest with your customers and tell them, hey, you need to BUY a 3rd party backup solution to make sure your Windows Guest OS's are backed up correctly.
so vmware get cracking, stop being lazy and build out REAL VSS support for your vmtools.