If you haven't seen Citrix's new Success Accelerator for XenDesktop, you should check it out before doing any size deployment (i.e. 10 to 1000s). I wish we had this 12 months ago when we started our pilot. It is in a Q&A format and gets you thinking about all the technologies involved and what choices you may need to make. It will walk you through the Design, Implementation and Rollout phases and provide an output of instructions and resources for your project. Definitely check it out.
Screenshot of the web ui is below.
