An MCT friend of mine Desmond Lee has written an excellent article on setting up OCS to test in a Hyper-V virtualised environment. If you’re at all interested in the stuff you can do with OCS (it’s pretty cool), you ought to go over and read his article and try it for yourself. Good stuff Desmond!
PS Have you seen the new OCS Website? http://www.microsoft.com/uc/products/ocs2007.mspx