As far as I can tell, Mercurial is being actively developed (i.e., updates being pushed out on a roughly monthly basis), and it's also actively being used. It isn't used as much in the open source community (probably the GitHub effect), but that doesn't mean it's "not looking real healthy" (anymore than OS X does compared to Windows).

Bazaar is a different story. Technically speaking, Bazaar isn't going away anytime soon. Canonical's development depends too much on it. The primary problem with Bazaar is that updates on Canonical's side are pretty much limited to dealing with issues that Canonical has, and there is little activity with respect to getting other bugs/issues fixed/addressed.

This is unfortunate, because Bazaar does do a few things better than either Git or Mercurial.