So there are substantial additions although the majority is in the Appendices.
There are lots of new races, new creatures, new classes and expanded options for playing as Klingons or Romulans.
A couple new ships added (Bird of Prey baby!) and some general clean-up and clarifications that should make it easier to understand and play.
If you are looking for TOS era inspirations while you are waiting I can recommend the Vanguard series of novels---or the newly released FREE series Four Years War novels (based on the old FASA ST:RPG supplement) from Stephen A. Fender.
Mr. Fender has a new kickstarter for a Romulan War novel series and a Four Year War Tech Manual!
Two Cover ideas: 70's style (left) and 80's style (right)--any thoughts?