I’m going to be very curious if this actually goes anywhere. During the Bazaar retrospective, I remember Jelmer commenting that one specific feature of Bazaar—its ability to work transparently inside Git repositories—was a misfeature he regretted. I was a bit surprised by that at the time; Mercurial generally feels that it’d be great to have better interop with Git, and there have even been projects such as hgit (directly use the Mercurial UI on .git repos) and hg-git (use Mercurial to clone and work with Mercurial copies of remote Git repositories; this is also the track I took in Kiln Harmony) to try to achieve that.
(BTW, neither hgit nor hg-git are official Mercurial projects, but both were started by core Mercurial contributors, and the latter remains very actively maintained.)
I’m not personally convinced there is enough interest in Bazaar, or enough legacy Bazaar repositories in active use, to really justify maintaining Bazaar at this point, but I’m really unsure that there’s enough room in this space to launch an third island of DVCS into the existing landscape. The ability to use Bazaar to work with Git seemed like one of its few bright stars; I’m not sure how Breeze will get any initial traction at this point.
Nit: hg-git was actually started by a GitHub employee (he got to it a few weeks before our GSoC student was to work on the very same thing). In order to help the GSoC student, I made the code more pythonic and added some tests, and then ended up holding the bag for several years.
I’ve since given up maintainership of hg-git, because I never use it. I still want to try hgit again some day, but there’s many miles of core hg refactoring to go before it’s worth attempting.
My only experiences with Bazaar have been SUPER painful - trying to pull down the latest emacs sources took HOURS.