These are bit dated news (well, only two weeks or so), but the fork/exec rewrite of DBus server was merged into master branch. The main aim of rewrite was to allow several concurrent synchronisations to be done (provided that the sync sessions don't conflict with each other). It wasn't possible before, because libsynthesis (the main library used for sync) does not have asynchronous API. There were two solutions: either use threads or spawn children processes doing syncs. The latter solution was chosen, because Patrick Ohly did not want threads to avoid complications with some possibly thread-unaware libraries. (Of course waiting for libsynthesis to get asynchronous API wasn't an option.)
The rewrite involved splitting the code in one file of syncevo-dbus-server into several files and then detangling all tightly coupled classes - I guess that the result is quite nice compared to what it used to be. In the meantime new C++ DBus layer based on GLib GDBus was added. Most of this work was done by Chris Kühl - I was mostly helping in fixing issues in new DBus layer and then working full-time on it and the code using it. As a final step I ported command line test from C++ to Python, so our work could be proved to work.
This was a really long task, very often I felt that I was losing grasp on the code I was working on and probably sometimes I had actually lost it. Now I feel happy to see it finally merged into master.