Windows and R12

Closing up our spotlight of Steven Chan's EBS blog for the week, is this article where R12 is certified for running on Windows 2008 Servers in Windows Server 2012 Hyper-V clients.  Why is this important?  Oracle on Windows is now fully certified inside and outside VM clients!  I remember several years ago when we were going to Solaris VM containers at a company level to save resources in non-PROD environments yet our group wasn't able to shift solely due to the certifications or support that was available at the time.  That leads me to wonder just what environments are NOT supported or certified to run Oracle?