Windows HPC Server 2008 RC1 is announced and made available for download via http://connect.microsoft.com. Register for the “Windows HPC Server 2008” beta program. You’ll also want to grab the corresponding SDK. Please do provide usability feedback using the “Feedback Tool” on the beta program web-site.
For technical discussions, join and participate in the Windows HPC forums accessible via the “Forums” tab on http://windowshpc.net.