Windows Server 2012 R2 is scheduled to release on October 18, 2013, along with Windows 8.1 and System Center 2012 R2. However, when Windows Server 2012 R2 publicly releases, Microsoft will not support the installation of SharePoint 2013 on the revamped server operating system. In a blog post, Microsoft states that SharePoint 2013 will receive Windows Server 2012 R2 support from SharePoint 2013 Service Pack 1 (SP1), but they also state that a release date for the service pack is still to be determined.
In a day when Microsoft has instituted quicker product releases, it might seem strange that something as popular as SharePoint might not see support right away when a major product liked the server operating system is updated. But, it makes sense when you remember that Microsoft recently proclaimed a "Cloud First" development plan. This means that unless a product update or support need has a Cloud-value focus for Microsoft, it gets pushed down the list of to-dos. Customers can easily utilize SharePoint 2013 in the Cloud instead of running it on-premise, which is just another example of Microsoft gently prodding Enterprises to the Microsoft Cloud.