VMware is known for being a little aggressive with competitors (namely Microsoft and Citrix) when they release new products.
Sometimes the company hits with public statements (like the ones against the Microsoft partnership with XenSource, against the Microsoft licensing policy for virtualization or against the Citrix acquisition of XenSource), other times they hit with private emails to the Sales partners (like the one against the Microsoft partnership with Citrix).

This time the target is the-once-great-partner Citrix and its just released XenDesktop.

The same day the product was finally released, VMware sent a letter to its partners completely destroying the value of the Citrix solution.
Among the other claims, VMware states that the product marketing message is misleading and confused the press, that the software is complex, poorly integrated and most of all built on a platform that has an uncertain future.

This last part obviously is the most interesting one.

In one of the previous attacks mentioned above, VMware already instilled the doubt that the Citrix hypervisor may be dumped by Microsoft as soon as Hyper-V becomes available, but now the company says something more:

Both Citrix and Microsoft have stated that Microsoft Hyper-V hypervisor will replace XenServer. Customers who deploy XenDesktop will use a virtualization platform that has an uncertain future.

At virtualization.info we agree that at today is not clear yet how Microsoft and Citrix will share out the market, but so far we didn't track any news reporting that the two companies plan to drop XenServer for Hyper-V. Quite the opposite.

It will be interesting to see how Citrix (and Microsoft) will answer this new attack. This post will be updated accordingly.

Update: Obviously Citrix refuted the statement about a possible drop of XenServer, publishing a long summary of how its hypervisor and Microsoft virtualization products will be integrated and not replaced by each other.