From two different sources, a Beast Hunters Movie is to be released towards the end of this year (direct to TV & DVD).
And one of the sources also mentions that this third season of TFPrime, will be the last. (seems like Hasbro doesn't like going beyond 3 seasons with Transformers cartoons)
That report does mention a new cartoon/series for 2014 though, but should be part of the Aligned universe, since Hasbro have been investing quite a bit into that storyline in recent years.