[...]it appears that [the] early 2013 slot is being set aside for Avengers writer/director Joss Whedons S.H.I.E.L.D. television series, which were hearing will begin filming as soon as next January.
S.H.I.E.L.D. is developing under Whedons guidance, and hes working alongside his brother Jed Whedon and sister-in-law Maurissa Tancharoen; the trio previously collaborated on the Dr. Horribles Sing-Along Blog mini-series and Dollhouse TV show, while the latter duo have also written for Starz Spartacus. Whedon is planning to direct the pilot (which hes also co-writing), while Tancharoen and her husband are expected to assume the bulk of showrunning duties thereafter once Joss starts to work full-time on the Avengers sequel, that is.
Varietys Marc Graser has the scoop on S.H.I.E.L.D. starting production in January 2013, so there should be several big casting announcements forthcoming over the next month. So far, Ming-Na Wen (SGU Stargate Universe, Eureka) is confirmed as one of the leads in the show. Meanwhile, Clark Gregg is prepped to reprise his fan-favorite role as Agent Phil Coulson, which is an announcement that has incited much speculation about where the series takes place in terms of the Marvel Cinematic Universe (MCU) timeline.