Even though it seemed for a while that MSDN and Technet subscribers would not get early access to the latest Windows versions, Microsoft decided to listen to customer feedback and reconsidered.
As a result, they just made the RTM versions of Windows 8.1 and Windows Server 2012 R2 available for MSDN and Technet subscribers. General availability for both Windows 8.1 and Windows Server 2012 R2 is still October 18. For the official statement, read this blog post.
Personally I’m very stoked about Server 2012 R2 and I’m already running the preview version. I especially love the improvements on Hyper-V and de-duplication. For more information about new and improved functionality, take a look at the free e-book : Introducing Windows Server 2012 R2 Preview Release.