I agree with Mr. Bultitude's answerMr. Bultitude's answer and would likewise implement bounties on metas by linking to the parent site's rep and features (i.e., rep taken and added from main site profile, and the question listed in the associated main site's featured quesitons).
In fact, I came here after looking for it on a site where I'm a mod – i.e., where I can already set the featured meta posts – because there are some issues that we need to resolve promptly in early beta and we want to attract the maximum amount of attention and thought to them before they're settled.
Failing that, I guess at least we have featured, and any user can suggest the mods tag a post as such. That's pretty good for the attention-getting piece, but doesn't do anything for the motivating/rewarding piece.