[Update: RTM version is released on 8/29/2008 - see http://blogs.msdn.com/hakane/archive/2008/08/29/team-system-web-access-tswa-2008-sp1-available.aspx]
We have just shipped the Community Technology Preview releases for Team System Web Access 2008 SP1 Power Tool and Work Item Web Access 2008 Power Tool.
Please note that these are "preview" releases and it is not recommended to use them in a production environment, however please feel free to download and give a try, and please send us your feedback.
Team System Web Access (TSWA) 2008 SP1 (CTP)
Work Item Web Access (WIWA) 2008 (CTP)
The final RTW releases will be shipped at the same time with TFS 2008 SP1 RTM.