Not sure if it is true but I heard today that 2Entertain plan on animating The Ice Warriors and The Tenth Planet next.
I'm not sure about Tenth Planet, but I know that a while back David Troughton said that he had taken part in a documentary about his father for inclusion on The Ice Warriors.
Tenth Planet, as far as I know, is being held back for a while, but a trailer was recently rated by the BBFC which all but confirms that Ice Warriors is coming. I imagine they will announce it once The Crusade is out so that it doesn't steal the thunder.