Joss Whedon, who recently signed a fairly comprehensive deal with Marvel that included writing/directing The Avengers 2 but also a larger creative role with the company, will write the pilot episode for the new series along with brother Jed Whedon and Maurissa Tancharoen. It is uncertain if Whedon will direct the pilot, though it's very likely.
Joss and Jed Whedon will executive produce along with Tancharoen. Jeffrey Bell, who co-produced and served as show-runner for Angel, will also executive produce and it is highly likely that Bell will assume show-runner duties once a full series order comes through.
Can ABC use the post-Avengers buzz to create a hit series or will Joss Whedon's notorious bad luck with TV shows end things before they even got started? At the very least the Marvel/ABC partnership will be more encouraging and supportive than Fox were during Whedon's Firefly/Dollhouse years.
The series is expected to have a heavy espionage-slant weaving in superheroic/comic book elements throughout, it is also likely they will use this weekly platform to help build on future movies. It could even potentially be used as a launching pad for other franchises - back-door pilots are the norm in TV-land, so we could see SHIELD introduce audiences to a host of exciting new characters; all vying for their own show!
These are definitely exciting times for True Believers everywhere, the Marvel universe continues to expand in ambitious and exciting ways, meanwhile DC/Warner Bros. still can't figure out how to make a movie that doesn't feature Batman.