I know everyone knows Windows 8 went Release Preview. You probably are downloading it or already downloaded. As a infrastructure person, you might want to check out Windows Server 2012 Release Candidate too! It is released together with Windows 8 RP. There are some huge changes that I see. There is a feature comparison document release on Comparison between Windows Server 2008R2 Hyper-V and Windows Server 2012 Hyper-V. There are some very interesting figures there. Make sure you take a look. It also describes what are the features not supported or partially supported in 2008 R2 Hyper-V that becomes fully supported in Windows Server 2012 Hyper-V. It is a pretty exciting list. Below is a high level comparison, and some are quite different from previous beta release. 
Not only Hyper-V is improved, there are a lot more new features coming with Windows Server 2012 RC. You can download the White Paper for the RC release and have a detail view on what are the new features.