Well when we get this started I kind of want to build it into a sort of bigger marvel universe. The S.H.I.E.L.D. agents will only be the beginning. Once we handle them bringing down H.Y.D.R.A. they can reform S.H.I.E.L.D. or something(Maybe work together with the X-Men) and our current characters can become sort of secondary character and our next characters can take center stage. Only they'd probably be younger. Teens maybe. You know because the whole next gen scenario set up. 
Only the build and transition will mena we won't all be human. We can be mutants, altered humans, etc. and the next crop may be related to other Marvel universe characters.