My original pitch for Captain Marvel was just a five-issue arc. Though I pitched a few arcs that would have taken us through probably a first year. Famously, the Falling Star arc was supposed to come first, but Marvel got excited about the Nuclear Man stuff and all Carmen's "Mad Max-y" designs and decided to go with that arc first. Everything from then on was just planning arc to arc. I don't think any ideas got cut, it was more just that some things I would have liked to do didn't fit with other things going on in the Marvel U (i.e. I love Mystique and would have been interested in featuring her -- but for where Mystique is at right now it didn't make sense to use her -- and I'm sure I wouldn't have been allowed due to other things going on with her). I had also been wanting to use The Brood (and X-Men!) since day one, but fortunately that one panned out for our final arc -- issue #49 is out today! ;D