Jeph Loeb, Marvel’s head of TV, is ecstatic about working on the S.H.I.E.L.D. pilot.  Loeb told Previewsworld, "Working with Joss, Jed Whedon, Maurissa Tancharoen, and Jeffrey Bell is a blast. And bringing in Clark Gregg to play Agent Phil Coulson--the best!  Hopefully we can be on the air in the fall of 2013 on ABC."
Loeb is not the only one to express excitement about the prospect of a S.H.I.E.L.D. TV series.  ABC TV’s President Pat Lee admitted to being both optimistic and excited about the potential of the Whedon-penned pilot, though he cautioned that "it was still early days, and it’s a long way to go between now and a successful series" (see "ABC Prexy Call’s 'S.H.I.E.L.D.' Series 'Very Joss Whedon'").
Given the amount of work that is being done on the S.H.I.E.L.D. pilot it makes sense that Marvel is hoping to produce the pilot in early 2013, which would mean a fall 2013 pickup by the ABC, if the network likes the show.  Of course there have been numerous TV pilots based on comic books from NBC’s Wonder Woman, CW’s Aquaman, and FX’s Powers that were never picked up by the network. 
On the other hand, given Joss Whedon’s track record in both TV and movies, and Disney’s interest in synergistic use of its Marvel Studios arm, the odds of a S.H.I.E.L.D. series being picked are better than most pilots.  While it is true that very few of 2012’s new shows are flourishing, the comic book-based Arrow is among the best performers of the new crop.