After months of testing, beefy Star Trek Online update Season 5: Call to Arms has been released.In a nutshell, Season 5 brings a Duty Officer System, the story of The Borg Advancement, Klingon gameplay updates, a skills revamp, a mission revamp, lore missions and economy restructuring.STO executive producer Stephen D'Angelo offered an overview of the changes in a dev blog.Star Trek Online turns free-to-play on 17th January 2012.New and Improved Content
  • Borg Invasion of Defera - An all new action ground combat map that features multiple play areas, boxes, and a variety of game play.
  • Re-envisioned Borg Strategic Task Force (STF) maps - These were cleaned up and streamlined to improve play. Then they were given a "Normal" version so everyone can experience the content, as well as an "Elite" version for some seriously challenging play. And finally, we threw in some great new rewards and elite gear that you can earn.
  • Federation and Klingon Academy - All new academy maps to explore and do non-combat game play.
  • Lore Missions - A whole new type of non-combat play. Learn about the Star Trek universe while playing these fun little missions.
  • Patrol Mission Revamp - The patrol missions got a new feel, now requiring some exploration to discover them. They also got better Skill Point rewards.
  • Event Calendar - A new event calendar that features nearly a dozen new events that happen around the clock.
  • Threaded Storyline - The whole storyline for STO has been put together in a cohesive way by threading the Episode content. Now it's easy to know what to do next, and to play through the core storyline.
  • Tighter Klingon Storyline - The Klingon game play was tightened up to play starting at level 21, so that the whole experience for Klingon play is improved.
http://www.eurogamer.net/articles/2011-12-02-star-trek-online-season-5-call-to-arms-release-notes