Lucasfilm publicist Tracy Cannobbio has confirmed that Star Wars Rebels will go on a midseason break after the television airing of "Gathering Forces," the episode set to air on Monday, November 17th. The series will be on a holiday hiatus until January 5, 2015. You can read Tracy's tweet with the confirmation here:
The hiatus has come too soon! But, it was expected considering Star Wars Rebels only has a sixteen-episode first season. Hopefully the wait will be worth it—"Gathering Forces," which is available now on WatchDisneyXD.com, is a great end to the first half of the season. You can see the preview of the episode here.