I know that the kickstarter campaign did not get to the Two Medicine Formation (so sad) but at least we will have character costumization, multiplayer, post-impact survival and environmental hazards (these last two are specially exciting). But the creators did not denied a Two Medicine Formation spin-off, and the idea is supposed to be fluttering the air. So, it's not dead.
They said they were going to introduce Gorgosaurus and Rubeosaurus (then Styracosaurus) as playable animals. But a full Two Medicine Formation should have more playable animals and here is a poll for these new creatures that could be playable. If this poll gets to more than 460 votes, the four additional animals will be added to the fictional game (yes, this is obviously not official).