As posted here a week ago, I am now using github to publish my work-in-progress code. Currently there are two branches of interest there: sculpt masking and the skin modifier. When I make larger changes (such as the recent skin-modifier work) I usually post here, but I am actually updating the branches fairly frequently at this point, at minimum pulling in the latest updates from trunk, as well as bugfixes. So if you are interested in making experimental builds, no need to wait for a post here, just watch the blender-bishop repository on github.
I’ve just pushed some updates to the masking branch (fixing an undo crash and increasing the mask brush strength.) I also want to point out the nice new mask brush icon contributed by Julio Iglesias.