You can find the details on the all new Windows HPC Server 2008 here.

It's exciting to see this move into a second iteration and build on some of the capability delivered in CCS Edition 2003. Main big features appear to be:

• New high-speed networking support
• Highly efficient and scalable cluster management tools
• Support for partners’ clustered file systems
• Advanced failover support
• Service-oriented architecture (SOA) job scheduler expanding the HPC market

There are 25 case studies on the site, and I've contributed to 2 of them here and here.

On the subject of HPC, Joe Hummel of Pluralsight (remember the CCS training?) has a great blog post here on using Mac Minis as a portable cluster. Brilliant.