I just wanted to let you know that the Product Group has released an update that must be installed in your farm before you can install any future Service Packs or Cumulative Updates. This applies to both Versions of SharePoint 2013.
You must install the following packages:
SharePoint Foundations 2013 http://support.microsoft.com/kb/2768000
SharePoint Server 2013 http://support.microsoft.com/kb/2767999
As always if you have just SharePoint Foundation then you need to install only that package. If you have SharePoint Server then you need to install both packages.