Mike Attili has a posted a couple of useful things for using the Team Foundation beta.

If you are tired of getting the "Unable to locate control: ctl00oReportCell" message, check out his solution to elminating the problem in Eliminate ctl00oReportCell error in Team System Project Portal.

He also provides a guide for setting up a group and assigning the permissions in TFS, Rosetta, and SharePoint to allow users in that group to successfully create Team Projects.  See Simplify Authorization for Team Project Creation.