So, on May 21st, we're getting a whole new side, along with expanded content for 1-20 on the Klingon side.

http://sto.perfectworld.com/legacyofromulus

Yep, it's the Romulans. One nice touch: Romulan players will be able to choose to ally with either Feds or Klinks and fly their ships too, in addition to their own (and also join respective side's player fleets, which is nice if your buddies already have a max rank fleet).