Exchange 2013 SP1 will arrive in early 2014, along with SP1s for other Office 2013-branded products. In a blog post Wednesday, Microsoft said SP1 for Exchange Server 2013 will permit Microsoft's mail server to run on its latest server operating system, namely Windows Server 2012 R2. Some folks may be surprised to find out that Windows Server 2012 R2 does not yet support running Exchange Server 2013. Exchange server support for a new Windows Server version is typically included in the next service pack. Read the full detail here at TechNet Blogs.
While the details are limited, Microsoft has released a few bits of information in regards to their upcoming Service Pack 1 release for Exchange Server 2013.