If you always want to be up to date with the latest version of operation system and you are running SharePoint 2013 in your organization, you’ll might want to wait a little bit. 

Installing SharePoint 2013 on a WIndows 2012 R2 server is not yet supported.

This recent TechNet article from Bill Baer confirms it: http://blogs.technet.com/b/wbaer/archive/2013/09/22/sharepoint-2013-support-for-windows-server-2012-r2.aspx 

You will have to wait until Service Pack 1 for SharePoint 2013 comes out.  Meanwhile you’ll might find tips and tricks to get around some issues, but it still not supported as of today.