The script for the 2007 Doctor Who episode "Blink" by Steven Moffat has been placed on the preliminary ballot for the Nebula Awards. The Nebula Awards are awarded yearly by the Science Fiction and Fantasy Writers of America (SFWA) for the best science fiction written in the previous two years, using a system of "rolling eligibility". Moffat was nominated last year for his script for "The Girl in the Fireplace", but lost to the Hayao Miyazakianimated film "Howl's Moving Castle".
This year, the other entries for Best Script are the screenplays for the films "Children of Men", "The Prestige", "Pan's Labrynth" and "V for Vendetta"; an episode of the television anthology "Masters of Science Fiction" written by Harlan Ellison; and an episode of the fan-produced Internet series "Star Trek: The New Voyages".
CLARIFICATION: "Blink" is on the preliminary ballot, which is the first part of a two-stage voting process. The final ballot will be released in March.
(Thanks to Alex Frazer-Harrison.)