Finally the details are out. Check out this page for all the features in all the different SharePoint 2013 flavors (the SharePoint On-Premises stuff is way down on the page):
Office 365 Versions: http://technet.microsoft.com/library/jj819267.aspx
SharePoint 2013 Version Comparisons: http://technet.microsoft.com/library/jj819267.aspx#bkmk_FeaturesOnPremise