Yes, the Terran Scout, Jenquai Seeker and Progen Privateer are in-game and usable with their very own individual starting areas. They are quite fun to play with each adding just a little something to their faction. For instance, Proggies now have a reactor builder in the PP.
The TS is my own favorite. TS is the fastest class in the game with Afterburn, can mine, has negotiate and can use missiles.