Unconfirmed as of yet, but according to TV.com Episodes 15 and 16 which will be the follow up to the epic Savage Opress story arc (Episodes 12-14) are named and have release dates:
Episode 15: "Overlords" will air 1/28/11.
Episode 16: "Altar of Mortis" will air 2/4/11.
"Dark Ahsoka" Trailer which may come from these episodes: