This document provides direction and best practices for running  BlackBerry® Enterprise Server on VMware® Infrastructure 3 or VMware  vSphere™ 4. In addition to providing information on architecting  solutions, the document also provides results of recent testing done  jointly by VMware and Research in Motion (RIM®), which characterizes the  performance and functionality of Blackberry Enterprise Server on VMware  virtual infrastructure.

http://www.vmware.com/files/pdf/Blackberry-Enterprise-Server-Deployment-Guide.pdf