If you are looking information on if you can run SQL Server 2008 on a Hyper-V the folks in the SQL Server Customer Advisory Team (www.sqlcat.com) have put together a whitepaper on best practice recommendations on just this topic:

http://sqlcat.com/whitepapers/archive/2008/10/03/running-sql-server-2008-in-a-hyper-v-environment-best-practices-and-performance-recommendations.aspx

For TFS customers wanting to run the entire stack on Hyper-V this white paper should help you evaluate and test the configuration as it relates to SQL Server.

Best regards,

Bryan