They never said December. Even last April at the New York auto show when the 2013's were first announced, they said the Hemi 8 speed would not be available until after the new year.
They were originally scheduled to start production in January but that got pushed back to March(this is according to Donlen's site, I don't think there was ever an official announcement stating that). They are now apparently beating the revised March 4 date.
GM's 2014 rollout made me laugh.