Yep. “The Guardians of Prophecy” (aka “The Place of Serenity”) will be released as a full cast audio drama by BIG FINISH in the UK in May 2012.
Information about the story can be found here:
http://bigfinish.com/304-Doctor-Who-The-Guardians-of-Prophecy
The story is a sequel to Johnny’s 1981 Doctor Who 4 part story “The Keeper of Traken” starring Tom Baker as The Fourth Doctor. It was originally submitted for transmission in either the 1985 or 1986 season of Doctor Who and would have starred Colin Baker as The Sixth Doctor with Nicola Bryant as Peri.
Along with “Children of the Gods”, it’s nice to know that 2 of Johnny’s most famous “Lost Scripts” will see the light of day next year B)