Fedora 20 "Heisenbug" will no longer ship next week as scheduled but has been revised now for a 17 December release target. The final release is delayed by one week due to a number of outstanding blocker bugs. The blocker bugs affecting the final release mainly come down to numerous Anaconda installer issues, the Fedup upgrade utility, the Fedora release notes, and there's also a few KDE bugs making the blocker list.
Confirmation of the delay was made via the Fedora devel-announce list. Hopefully the 17 December date is met otherwise it could be difficult to ship Fedora 20 in 2013 due to the Christmas and New Year holidays.