Mark Henry's WWE status is described as a touch-and-go situation. The Wrestling Observer reports that Henry was supposed to be back a while ago but he is still having shoulder injuries. There have been rumblings of Henry not returning but most expect him to be back before WrestleMania.
Christian is still scheduled for a return before mid-January, in time for the Royal Rumble. They still haven't decided if he will be returning as a babyface or a heel yet.