After fmg/my experiments with GtkModule didn't work out, in my case due to public/private API/member access, I decided to take a step back and look at other solutions. As it stands at the moment, in terms of GTK3 support, I think the best plan would be to go down the Cordia based route I started with but get it running on top of fmg's Fremantle-GTK2 port. It should provide enough basic features to allow some GTK3 apps to be Hildonized. The plan would be to use it as a transition to convert some Hildon code to stock GTK. At the moment work on this side is on hold until I can sit down and get a working Fremantle-GTK2 environment up and running.

My other project was, as you said, to move away from requiring hildon-desktop for a future libHildon applications. Elements like stacked windows and menus are the main parts I am looking at. Taking my GTK3 port, it will run under XFCE for example but features are broken. This experiment was looking at replacing HildonStackedWindow and related functionality with a GtkWindow featuring a GtkStack. After fighting few issues (pop 2 windows and it showed window @ 0 instead of the top of the stack, tracking actual stack size) I did get it to a point where it was almost what I wanted. The problem is the close button. You can listen for close button messages and pop windows until you have only one where you actually close but you can't change the icon as it is themed by the window manager. Next option was to hide default button and use your own, but you can't make use of window manager close icon on your button. Third option is to make a variant using both wm and a GTK button and show/hide the relevant one. It's a messy solution. This was going to form part of a Hildon/Weston-based Wayland experiment.

Just checked out the video. Looking good so far.