Yes Hart said that there will be a christmas episode (because he is trying to get Zooey to star in it) and there is going to be a halloween one I think.
they had a Christmas epsoad in the first season when Zach and hodgens almost blew up the lab, and then they had a hawleen epsoad because Zach was dressed as the front of a cow, and Booth was dressed as a "Squint" and Brenna was dressed as Wonder women