The aborted Doctor Who story written by Douglas Adams and would have been the last story for season 17 will see what exists on DVD sometime in 2012. It was announced earlier this week on twitter from ClassicDW:
Plans are to release the SHADA fragments together with MORE THAN THIRTY YEARS in a box filled with other content goodies! Likely 2012.
And for fans of the Zygons it is not expected to see release in 2012 so maybe for the 50th this cult classic and pretty good Tom Baker story will finally get released.