The TFS Operations Guide has been published to MSDN.
Summary: You can manage your deployment of Microsoft Visual Studio 2005 Team Foundation Server more effectively if you create your own operations plan. As you create your plan, you should understand key elements of the architecture of Team Foundation Server and how your deployment topology affects operations. This white paper explains those elements in detail, so that you can avoid common problems with your deployment.
Most notable new features:
Read more on Brian Harry's blog: http://blogs.msdn.com/bharry/archive/2007/09/29/september-tfs-power-tools-released.aspx
The TFS to TFS Migration Tool is designed to enable the migration of work items and version control artifacts between TFS servers (including history).
Please note that this is pre-release: it's being published to help test and stabilize the tool before it's "official".