Cryptic announced that in the upcoming weeks they will release content updates which will bring Endgame raid Episodes, PvP maps and additional Klingon content.  More detailed info on these updates below:

The Hive Mind Is Everywhere

The Borg are invading! Just in time for many of you to reach the rank of Admiral, we’ve got three new high-level Episodes centered around the classic Alpha Quadrant menace, the Borg. Here’s what you can expect:

• Collateral Damage – Help save civilians caught in a battle between the Borg and Undine.
• Recovery – In this follow-up to Collateral Damage, Rescue colonists infected by the Borg virus and fight Undine determined to destroy them!
• State of Q – Q transports you back in time to do him a special favor.
• More to come!

In addition to our compelling scripted content, you’ll be able to check out a brand new, Borg-themed Deep Space Encounter. Can you and your friends hold off the coming invasion? It won’t be long until you’re called upon by Starfleet to save the galaxy!

Don’t forget to check out the new exploration content included in the Borg content pack, too. When you find some respite from the Collective, seek out new life and civilizations at your own pace. The universe is just waiting to be discovered.

Raid Episodes Coming Your Way

If you’re looking for a challenge, look no further than our upcoming Raid Episodes, which combine bold storytelling with our toughest five-man missions yet. These are just a few of the Raid Episodes we’ll be rolling out over the coming weeks, beginning a week after launch. Raid Episodes are available to both Federation and Klingon players.

• Infected – Investigate a federation station that Starfleet has lost contact with.
• The Cure – A planet has been completely taken over by the Borg. Fight them for control of the planet.
• Khitomer Accord – Travel back in time and uncover and participate in the events that led to the release of old Borg you encountered in the Tutorial Episode.
• Into the Hive – Track down a missing Starfleet captain and come face to face with the new Borg Queen.

More Action in the Alpha Quadrant

We’ve got even more great additions planned for Star Trek Online. Here’s just a bit of what’s coming:

• Klingon Fleet Actions – Form up with your closest friends and do battle in large engagements.
• A New Klingon Ship – You asked for it, we made it: A Tier 2 Klingon Battle Cruiser.
• Klingon Star Clusters – Seek out new life and civilizations … and subjugate them! Additional PvE content for the Klingon faction.
• Federation vs. Federation PvP – Practice against your allies before engaging your enemies.
• New Ground Maps – We’ll be adding a new Ground Assault PvP map, as well as a new ground Fleet Action.
• More IP Locations – Check out Rura Penthe and our whole solar system, from Mercury to Pluto.

Source:   http://www.startrekonline.com/node/965