Web client is nice thing as it do not require any installation on clinet machine. It is also cross platform, but what I feel is that - it is a stupid idea to enforce third party plugin to be developed only in flex. I don't see any rational behind this. Now plugin developers have to have knowledge of Flex, and existing third party client applications have to rewrite into flex if not written in flex for future support. VMWare should learn from other products, e.g. Symantec's Veritas Operations Manager (VOM). Although VMWare has copied many things from VOM into web client but it fails to implement undying flexibility that VOM offers.
Thanks,
Prithvi Zankat