At Citrix iForum The App Delivery Expo, presented by Citrix, Mark Templeton used the keynote launch a new product called "CItrix XenDesktop." XenDesktop will be a combination of three products: Citrix Desktop Server, XenServer (formally XenEnterprise), and Citrix Provisioning Server (formally called Ardence).
The focus of XenDesktop is to simplify desktop virtualization and to combine everything you need into a single product: the delivery, the virtualization, and the image provisioning.
Previous version of Citrix Desktop Server worked with VMware, and Citrix XenDesktop will still technically work in this way. But of course Citrix is focusing on Xen as the virtualization engine ultimately.
Citrix has setup a dedicated page at http://www.citrix.com/xendesktop for this product. Next week they'll make a freely-available download available.