In case you missed it, there is a war on between the two major proponents of desktop virtualization.
On one side you have VMware pushing a new architecture called VMware View that is based on a new protocol called PC-over-Internet (PCoIP). On the other side, you have Citrix allied with Microsoft behind an enhanced implementation of its ICA technology that is now called the HDX protocol in the latest implementation of XenDesktop.
Both sides claim that their respective approaches will provide a truer desktop experience, with VMware arguing that its new technology has specifically been designed to support desktop virtualization, while Citrix argues that its approach benefits from all the performance experience Citrix has gained from supporting terminal services applications.
As neither side seems to be able to support their respective claims without any testing, the reality of the situation may be that neither technology is all that germane to the core issue. The odds are good that by tuning your network to support latency-sensitive applications running over either protocol, you can get desktop virtualization to work satisfactorily. The real question is do you have that kind of visibility into traffic on your network and can you optimize the performance of certain packets on that network.
And failing that, can your organization afford to upgrade the underlying networks and servers required to achieve a satisfactory experience for the end user. Both VMware and Citrix like to throw around a lot of claims about cost savings relative to desktop virtualization. But the infrastructure upgrades required to achieve those savings may be beyond the reach of a lot of IT organizations in the economy.
In the meantime, the tests that vendors or anybody else runs might not matter. The fact of the matter is that the performance attributes of every network are going to be different based on the characteristics of the applications that run on it. So if you're thinking that desktop virtualization is right for your organization, the only way to know for sure is to test the various offerings out there yourself. In this case, there is no substitute for experience.