If you are currently using Team Foundation Server Beta 3 Refresh or considering installing it, Allen Clark (PM – Team Foundation Server) has a few pointers for you on the Team Foundation blog. His main points are as follows;

• If you customize work item types, don’t create work item field reference names that have more than 70 characters, or that begin with a number.
  • If it’s not too late, deploy Team Foundation Server on the hardware you’re going to use at RTM.
    • If you are going to deploy to new hardware, go ahead and install Team Foundation Server on the new hardware and try it out just to make sure you don’t have configuration issues. You can uninstall Team Foundation prior to upgrading.
      • Keep track of the customizations you’re making to the process templates; you’ll need to do these again before you’ll be able to create new projects with your custom process templates.

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      Read his post here