The "Fall season finale"?  Yeah, only 5 episodes were produced  before the Christmas special.  Supposedly, this season was purposely short so more funds could be diverted to next year's budget, 2013, which is the show's 50th anniversary (November 23, 1963).  Whether that means we'll get more than the usual 13 episodes we've come to expect or more money invested into a fewer number of grand scale episodes, I don't know.

Sincerely,

Bill

Tempt the Hand of Fate and it'll give you the "finger"!