The new season of content, dubbed 'Call to Arms', features a new Borg invasion of Defera "action ground combat map," along with additional content.
'Call to Arms' also includes "re-envisioned" Borg Strategic Task Force maps, which have been streamlined to improve the gameplay experience before being given a free-to-play version and an Elite version.
No release was mentioned for the content; however, D'Angelo says that the content has just completed "two months of extensive testing." He also mentioned Tribbles, which is required by law in all conversations pertaining to Star Trek.
A full listing of changes can be found on the official Star Trek Online blog.