Currently I am working on deploying Windows 7 to a couple of Remote Call Center users using XenDesktop 5.5 and ShoreTel Communicator as a soft phone.  As I was testing some different headsets I received a message that my test user lost her connection to soft phone completely.  After pondering what was going on I realized that the XenDesktop image I was using was built of an image that ShoreTel Communicator client was launched on before putting it in standard mode. I started looking around and found that the client uses and End Point Name to connect to the server. I think looked at my test account settings and then the test call center users settings and found out that both were using the same End Point name.  Digging around the registry I found the following key

HKEY_LOCAL_MACHINESOFTWAREWow6432NodeEyeP MediaMgcpEndPointName

What I did was created a script that changed this key on logon and all was good.