Now if you double click on a rpm/deb file you will get the following UI:
You always get asked for the admin (or user) password so that this can't be abused by a malicious script when you have asked PolicyKit to remember your password.
We're a couple of weeks from the release of 0.1.0. There are no DBUS API changes planned in the near future, and we're just going though the list of blockers for release.
Join us in #PackageKit on freenode if you get stuck or you want to ask any questions. Thanks.