I was about to send a mail about it too. :-)
Basically, a new
art.gnome.org web site is going on (AGO3), as a SoC project. If I have some time, I would we've been working on an atom extension for themes on the current
a.g.o. web, and I did a small app to consume those feeds[0].
I would love to add support to the control center for this feeds, however, I would like to consolidate the services to do so and think of a good ui for it. The second step is in progress already, but with the first one I'm quite lost, merging several theming sources (gnome-look,
art.gnome.org) into one as a mashup and single point would be the ideal solution for this, so users don't need to handle those feeds within applications.