Traditionally delays in the Fedora release schedule have all been too common and it looks no different for Fedora 20. Due to some unresolved blocker bugs, it was decided today to postpone the Fedora 20 Alpha debut until the 24th of September.
Most of the bugs blocking Fedora 20 Alpha from shipping on time deal with the Anaconda installer and range from errors to problems with the boot-time LUKS pass-phrase. There's also still items like preparing the Fedora 20 wallpaper and updating the Heisenbug release name. The bug list can be found on this qa.fedoraproject.org page.
Delaying the Fedora 20 Alpha release also pushes back all other milestones, which means rather than shipping Fedora 20 Alpha on 26 November it will not ship until early December. Of course, there could be further delays with the alpha, beta, or final release, as has been the case for past Fedora Linux release cycles.
Hopefully Fedora 20 will be out by Christmas due to its Wayland Technology Preview, virtualization improvements, and other great features.
The Fedora 20 Alpha slip message was posted this afternoon to Fedora's test-announce.