The Doctor Who spin-off Torchwood has always been notoriously uneven, but it seemed like its truncated third season would dodge that bullet. After all, it's just one five-episode story, "Children Of Earth," airing over the course of a week. And early reports made it sound as though the whole shebang would be written by series creator Russell T. Davies. But there's some bad news on that score. Davies will write one episode, James Moran ("Sleeper") will write another, and the remaining three will be written by newcomer John Fay. Oh well.[Blogtor Who]
that info is from Doctor Who magazine but there was a last minute change and Russell is actually writing the first and last episodes. Moran is writing one and Fay (who hasn't written for Who before) is writing 2 eps. Also the entire series is based off of a story by Russell T. Davies and is being directed by Euros Lyn (girl in the fireplace, the library two-parter, tooth and claw.) Russell has said it is going to be very much the director's series.