Here are the recent changes to the packaging guidelines.
-----
The section on the use of pregenerated code was amended to indicate the preference for having tools necessary to regenerate such code be free software and packaged in Fedora. * https://fedoraproject.org/wiki/Packaging:Guidelines * https://fedoraproject.org/wiki/Packaging:Guidelines#Use_of_pregenerated_code * https://fedorahosted.org/fesco/ticket/1514
-----
The outdated prohibition on socket activated services was removed from the Systemd packaging guidelines.
* https://fedoraproject.org/wiki/Packaging:Systemd * https://fedoraproject.org/wiki/Packaging:Systemd#Socket_activation * https://fedorahosted.org/fpc/ticket/618
-----
The Perl guidelines were modified to include information about necessary build dependencies now that Perl itself is being removed from the default buildroot.
* https://fedoraproject.org/wiki/Packaging:Perl * https://fedoraproject.org/wiki/Packaging:Perl#Build_Dependencies * https://fedorahosted.org/fpc/ticket/620
-----
The section on use of /run has been simplified.
* https://fedoraproject.org/wiki/Packaging:Guidelines#.2Frun * https://fedorahosted.org/fpc/ticket/622