I've been experimenting with gom, the GObject datamapper recently.
With a lot of help from Bastien Nocera, I eventually managed to get started using it as an experiment for one of my projects.
I have to say I'm quite impressed. Sure, writing GObject code is super verbose, but then managing objects and properties is so much nicer than managing strings full of SQL queries. And I hear the verbosity might be greatly reduced in the near future! :-D
Long story short, I've started building gom packages from Git snapshots in a Copr.
I'll eventually push it to Fedora proper, but I'd rather wait for an actual release. Maybe in time for GNOME 3.14?
In the meantime, if you want to try it out, go grab the packages from the Copr. Gom is under quick development, and now is a great time to test it and ensure it has the features your application needs. For example, I needed boolean properties and columns with a UNIQUE constraint, and both are now possible in master. :-)
Now to play some more with it...