A couple of months ago, Jeff Lucovsky wrote about filing watson reports for Team Foundation. When you log in as an administrator on the application tier for TFS, you may be greeted with a dialog asking if you would like to report errors to Microsoft. Likewise, if Visual Studio crashes, you may be asked to report the error to Microsoft. Please do this. Specific developers and testers for each of the components of TFS are responsible for making sure that the errors filed through the Microsoft error reporting service (aka Watson reports) are filed as bugs to be fixed. Each error report contains information about the state of the web service when the error occurred, such as the stack trace and the information passed in the HTTP request, to allow us to diagnose the problem.
If you look at the event log on the application tier (you can run Event Viewer by entering "eventvwr" in the Run dialog triggered by clicking the Windows' Start button followed by Run...), you will see events logged for errors that are reported using Microsoft error reporting (they'll be reported to us only if you allow them to be sent in the aforementioned dialog). If you look at the Application log type in Event Viewer, you can spot the events corresponding to reportable errors by looking for events where the Source column is Tfs and the Event column is 9000. The actual error event usually appears just before it (or it may be separated by a couple of other events).
You may not run into these errors, but if you do (remember, it's beta software), please consider reporting the errors so that we can fix them.