Kjell Ahlstedt has done some work on a new parallel-installable version of the libxml++ API, to fix some mostly-minor but annoying things that needed ABI breaks. You can see the code in libxml++’s git master.
He’s ready to release a stable .0 version soon. So now is the time to mention anything about the API that needs to be changed, please. People too often only look at these things right after the first stable release, when it’s too late.