Just because Hyper V Server 2008 R2 is free, its doesn't mean that Microsoft is not at all serious about this offering. If you have followed my blog in the past, you can see the feature set it brings on the table here
It has all the high availability features like Live Migration, Failover Clustering, Clustered Shared volume and that too completely FREE!!!
If you still thinking what kind of value, a free product can bring into your organization, Please check the following blog post from Jeff Woolsey, Principal Group Program Manager. Microsoft here
Trust me you are not going to believe that how much you can save by adopting Microsoft Virtualization and reinvest that dollars back into your business.
Read the Microsoft Official Blog here
Let me know your feedback and comments and stay tuned.. the party has just begun. ;-)