As of 6/18, there is a patch that fixes a critical upgrade bug and it can be downloaded here: http://code.msdn.microsoft.com/KB2135068 plase install this patch before installation but before configuration. A more detailed explenation can be found here...

Generally, the Server URL and the Notification URL should not be modified. Both these values are TFS-system-wide. So, if multiple application-tiers exist, modifying either one of these values will impact them on all application-tiers The Notification...