The Doctor will return, Joss Whedon promises.The long-awaited follow-up to the 2008 made-for-Internet hit “Dr. Horrible’s Sing-Along Blog” is still very much in the works, Whedon assures. He hopes to get it into production “within the next year,” Whedon said Tuesday. (He was pressed by Variety on the fate of the “Dr. Horrible” sequel after he moderated a Q&A with Mike Birbiglia and Ira Glass following a screening of the duo’s IFC feature “Sleepwalk With Me” at the Writers Guild Theater in BevHills.) The appetite for more “Dr. Horrible” will be whetted on Oct. 9 when the CW gives the offbeat, 42-minute superhero-tuner its first TV airing, as the kickoff to the launch of its fall season. One of the major hold-ups to producing the follow-up has been the fact that Whedon keeps “employing the people who will work on it” in other capacities, he noted. The original “Dr. Horrible,” which starred Neil Patrick Harris, Nathan Fillion and Felicia Day, was penned by Whedon and his brothers, Jed and Zack Whedon, and Maurissa Tancharoen. Jed Whedon and Tancharoen worked for Joss on his 2009-2010 Fox drama “Dollhouse,” and they have been recruited to help him co-write a pilot for ABC and Marvel TV this year based on Nick Fury’s S.H.I.E.L.D. espionage org featured in Joss’ summer blockbuster “The Avengers.” The storyline of the TV series will be “autonomous” to the features, Joss Whedon said. The “Avengers 2″ sequel is, not surprisingly, is already slated for a May 2015 release. If the ABC pilot is ordered to to series, Jed Whedon and Tancharoen would serve as showrunners with Jeffrey Bell. Marvel TV’s Jeph Loeb also exec produces. The original “Dr. Horrible” made a splash as a made-for-Internet event that preemed over three nights in July 2008 via free streaming, and then was made available as a paid iTunes download for a limited time. Joss Whedon said they haven’t decided how they’ll handle distribution of the follow-up but intend to take a “media-agnostic” approach to the production.