Progress with PackageKit is amazing. I've had lots and lots of patches from many contributors which is great, thanks to you all. There is still lots of library and API churn but the code and GUIs are being slowly developed into something useful. The yum backend is almost complete.
There's now a mailing list for PackageKit development. Please subscribe if you want notifications of new features, or if you have questions about the GUI or daemon, or if you are a backend writer. It's hopefully going to be a low-traffic list.
Also, the download location of the daemon is now:
git clone git://anongit.freedesktop.org/git/packagekit
Thanks to the fd.o admin for sorting out my project creation request.
edit: use the fd.o mailing list, not the google group. Thanks.