[Update January 28, 2010: Mike Sterling from Microsoft informed me that the article was erroneously published. There is still some work to be done internally before it can be made available]
Microsoft has a reputation of writing good best practices analyzers. Some of the newer ones are integrated in the Server Manager of Windows Server 2008 R2 (Active Directory, DNS) or its manager such as the Cluster Validation Analyzer in Windows Failover Cluster Manager.
A recent addition is the new Hyper-V Best Practices Analyzer
About the Hyper-V BPA Update
The update described in this article contains best practice benchmarks against a computer that is running Hyper-V on a computer that is running Windows Server 2008 R2. After this update is installed on a server that is running Windows Server 2008 R2, you can run a series of Best Practices Analyzer scans on Hyper-V that will help you to bring the role into compliance with best practices.
You can use Hyper-V Best Practices Analyzer to scan a server that is running the Hyper-V role, and help identify configurations that do not comply with best practices for this role. BPA scans the configuration of the physical computer, the virtual machines, and other resources such as virtual networking or virtual storage. Scan results are displayed as a list that you can sort by severity, and include recommendations for fixing issues and links to instructions. No configuration changes occur automatically by running the scan.
Currently there are no downloadable bits, but this will no doubt change soon.