My preference would be for a non-powered Carol Danvers first. Introduce her in Avengers as Fury's second-in-command (taking a cue from the Ultimate line), which would be a bit role than would then take on an expanded significance in the S.H.I.E.L.D. movie Jackson is supposedly signed up to do. In the final act of the S.H.I.E.L.D. film, she gains her powers, which sets her up for a spin-off of her own and participation in Avengers 2.
For this Avengers, I'm still hoping for the Wasp.
Fictitiously yours, Trent Roman