So far so good
The 2.6.0 GNOME Platform Bindings release happened a couple of days ago. I think it's a success because 3 bindings projects (C++, Java, and Perl) delivered API/ABI-stable wrappers just 2 weeks after the underlying C APIs, with reason to believe they are high quality.
Binding is inherently feature-based so it's difficult to squeeze it into a time-based schedule. But now that these projects are in sync it will be much easier to keep them that way. Stabilizing APIs is very stressful, because you constantly worry about the forgetting something you can't fix later, and you convince yourself that any single mistake could be catastrophic. For the Java and Perl bindings this was the first time that they had stabilized their APIs so I know that their maintainers felt this stress severely. But they worked hard and worried about all the right things, and they got there. They were even forgiving of the strict oversight to which I subjected them. The perl bindings actually stabilized their API/ABI before the scheduled date, even while their maintainer was becoming the father of twins.
I feel relieved now the 2.6.0 C++ bindings are officially API/ABI-stable. I can stop worrying because I can't even fix ABI problems if they turn up, and I can casually do any API additions in the 2.8.0 cycle. I think I'll reduce my gtkmm hacking to a couple of days a week now, so I don't waste all of this valuable "sabbatical" time. Also, I'll try to stay off IRC most of the time, because that massively saps my productivity.
It looks like GTK+ won't add new API for GNOME 2.8. I'm a bit disappointed because I love all development to be in sync. But I fully understand the need to take the pressure off. As a plus, it gives me a lot less C++ binding work to do during GNOME 2.8, and it will make it even easier for other Bindings projects to catch up. The gnome-python/pygtk team are already making test releases that wrap GTK+ 2.4, so they should manage it easily. And Gtk# are working on GTK+ 2.4 stuff on a cvs branch, so they are very likely to be full players during the GNOME 2.10 cycle. Hopefully some others (Ada?) will sign up too but all the major languages seem to be taken care of.