I'm new to Chipmunk and I have to say I like what I see

I'm interested in using Chipmunk to implement a Force Directed Graph based layout algorithm, in Ruby. For that I need springs and repulsion forces (coulomb forces). I've noticed that the current development branch has moved to a more generic approach when it comes to joints (constraints), which also allows a variety of springs to be modeled.
I'll try to use the latest svn, but I was wondering, when do you expect the next 'stable' release to be out?
thanks
Ioannis
PS: currently the demo doesn't seem to work. The window pops up but does not redraw