options:

if Jessica is White:
Liv Tyler
Gina Carano
Gemma Arterton (it wouldn't happen but I think she would more than rise to the occasion if the writing was top notch, which I assume it will be)
Teresa Palmer
Katee Sackhoff (she's on another show but if the role was right, I could see her leaving to be Jessica)
Jennifer Garner (hell she kinda already was a spy on ALIAS...but she's probably too old)
Emilia Clarke (if she wasn't on Game of Thrones and Jessica was just out of undergrad...)
Piper Perabo (same as Jennifer Garner, only replace ALIAS with Covert Affairs)

if they "diversified" Jessica (aka casted a role with an actress of color. won't happen but you never know):

N'bushe Wright (just put her in SOMETHING...find her lol)
Rosario Dawson (i'm throwing her in just for the hell of it. She probably wouldn't do it though)
Sanaa
Guga Mbatha-Raw (she WAS the best thing about that shitty ass UNDERCOVERS show on NBC)

But, they'll probably go with an unknown....


can't think of anyone else