Just a heads-up:
We hope to land a new PolicyKit version (which will turn into 1.0, eventually) in F12 soon. The new version simplifies the API and will require PolicyKit-using application to be ported. For more information, have a look at the feature page:
http://fedoraproject.org/wiki/Features/PolicyKitOne
It also has pointers to api docs and a (terse) porting guide. We already have a collection of patches for quite a few PolicyKit-using apps, so the transitions should be relatively painless.
Matthias