According to the Zap2It Online Schedule for GSN, the network will air NBC's version of Deal or No Deal (which ran from 2005 to 2009 with host Howie Mandel) on Christmas Eve (December 24th) from 8am to 6pm (ET). No word on whether The Chase will have a rerun or air at all on Tuesday night, but will most likely not be new.
There is currently no information on additional Christmas and New Years' marathons. Monday, December 23rd remains a regular schedule.
In addition for Black & White: Reruns of What's My Line? and I've Got a Secret will still air at 3am (ET) the week of December 23rd.