The title is clearly an exaggeration but nonetheless a warning. As we recently showed, under Citrix' regime, Xen(Source) grew closer to Microsoft and it's gradually losing its GNU/Linux focus and excluding/neglecting all those other than Novell and Microsoft [1, 2, 3]. The following new article, "Citrix CTO Mum on Plans to Build on Microsoft's Hyper-V", quotes what used to be a main man of Xen.
Simon Crosby, the CTO of the Virtualization and Management Division at Citrix, can't wait for Hyper-V to arrive. "The sooner that happens, the better," he said.
Just like it has done in the past with server-based computing, Citrix will extend the Microsoft platform to make it more attractive, according to Crosby, without elaborating on what the company is working on. "We haven't made any product announcements yet, but we will as Microsoft goes to market," he said.
He also sees opportunities for Citrix running its products on top of Microsoft's Hyper-V, for example, the recently launched XenDesktop.