First Steps with Tracker
I managed to package it within an hour and then decided to need a use-case for these new packages. I picked GNOME Launch Box and after some hacking, I managed to properly replace the application search module by a tracker based module. It was pretty straight-forward to develop that module (after getting a bit into SparQL).
I even ended up doing some more cleanups and finally dropped libgnomeui and libgnomevfs.
I'm really looking forward to replace even more backends with tracker-based ones.