NBC apparently hasn’t learned any lessons from Heroes or em>The Event.
With Revolution being one of the only hits the network has had it years, NBC believes that fans will come back to the show, even if it takes a few months off.
Revolution will be benched in January so NBC can launch another new series in its timeslot. It will then come back in late March to conclude it’s first season run.
NBC did the same thing with Heroes in its first season and The Event. Both of those shows never quite recovered their momentum out of the hiatus.