The next release following 3.12 will happen in March, 2015. So we havean entire year to stabilize the WebKit composer. Also the HTML library
that the composer is currently based on has been dead several years now,
and I personally would like to wash my hands of it as soon as possible.
I haven't tested the branch in awhile, but I've seen numerous recent bug
reports from Milan and Tomas seems pretty responsive in fixing them. As
long as that continues after merging, and we have a handle on the major
remaining regressions, I think it's a reasonable risk to finish the work
directly on the master branch.