From the Chris Sells:
To set your expectations properly, WinHEC attendees and MSDN Subscribers will have access to the M7.2 OS and SDK bits, but will not have access to any matching Visual Studio bits. Neither the PDC Visual Studio installation nor the latest Visual Studio 2005 community drop nor even the upcoming Visual Studio 2005 beta will install or run properly on M7.2 Longhorn. We're hoping for future LH Milestone drops to include the matching Visual Studio bits, but this one doesn't. Luckily, MSBuild is included along with the compilers, so you can still build LH code under M7.2 like the pioneers did when they were blazing the Oregon Trail. It'll put hair on your chest and build strong bones and teeth.
That's a real shame, but I guess we'll have to do... time to renew my friendship with mr. Emacs.
[Update: the ISO is available for download now at the MSDN subscriber download site, but with a size of 733.75 MB you'll need a DVD to burn it on.]