The Marvel Comics adaptation - a loose spinoff from Whedon's Avengers movie - will reportedly start filming in January 2013.
"It's very Joss Whedon," Lee told TVLine. "We're optimistic, because Joss is a genius and we love the idea and we love what we've seen."
However, the network head cautioned that it is still "early days" for the project, which will see actor Clark Gregg resume his Avengers role of Agent Coulson.
"It's a long way to go between now and a successful series," Lee acknowledged. "But we are very excited about it."
Former ER actress Ming-Na, The Fades star Iain de Caestecker, Elizabeth Henstridge and Brett Dalton are also attached to star in the S.H.I.E.L.D. pilot.
Previous Whedon collaborators Amy Acker (Angel) and Summer Glau (Firefly) have both expressed an interest in appearing in the potential series.
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Watch a trailer for Joss Whedon's The Avengers below: