Thanks Scoop who has let Neowin know that build #3689 (an offical OEM build) of Enterprise and Standard Server has somehow leaked to the Internet. This build will not be made available to Beta Testers and all signs indicate that this is a Pre-RC2 (Release Candidate 2) release.
Official testers are currently working with build 3678 of Windows .NET Server 2003 which was also one of the first builds to see the new name change to Windows .Net Server (Family) 2003 the year tag re-appearing after it was last used with Windows 2000 on the box. (Windows ME and XP followed 98 Second Edition for the client desktop)