Update: My mistake folks, i misread the information. Only the documentation regarding B2TR is released (guess I got carried away when I read "b2tr" and "released") ;) Thanks to Ishai Sagi for pointing that out. Well the moment we've all been waiting for is here! B2TR is ready to download ;) Make sure you read the the following documents before patching (or installing) you're fresh copy of the B2TR of Sharepoint 2007.
SharePoint Server 2007 B2TR Update Guide – This includes all of the update steps, known issues, workarounds and planning guidance. SharePoint Server 2007 B2TR Readme – This includes workarounds and fixes for less common issues for specific configurations.Check the Sharepoint Team's blog and Lawrence Lui's blog for more details