I'd definitely pay for a game with a campaign built on the foundations of the game. I miss good strategy games with nice long campaigns.
Tell us what your needing, coding and otherwise. Congrats on the great work so far also!
If you're a programmer, you can start here - http://trac.wildfiregames.com/wiki/GettingStartedProgrammers
In terms of where we most need contributors, at the moment I'm not aware of anyone working on campaign storyboarding or UI mockups.
[1] http://trac.wildfiregames.com/wiki/GettingStartedProgrammers [2] http://wildfiregames.com/forum/