I'm pleased to announce Browser Switchboard development release 3.3b1 for Diablo and Fremantle. Packages are now available in extras-devel and on the Garage download page. This is a development release designed to get new code into circulation; it's not received the usual level of testing and may be buggy.
Remaining things to deal with before 3.3: [Fremantle] Further improvements to the MicroB launching process -- the goal is to get to the point where the user experience when MicroB is selected as the default browser is identical to that when Browser Switchboard isn't installed. (Completely untested code implementing most of the ideas lives in the fremantle-microb-improvements branch in Git, if anyone wants to look at it.) In the UI, don't let the user configure a browser that's not installed. I can't promise a timeframe on any of this -- it could be a while before I have time to return to this project.