I have been tracking the mercurial project for a couple years now. First just a bookmark under python+scm, then after using hg to code on an airplane about a year later, I was hooked. I helped get the microformats testing effort using mercurial about a year later, and did some noodling on Access control and version control: an over-constrained problem? around that same time.
- fractal project organization (touching on PartiaClone and the ForestExtension)
- the toplogy of update flows in a large development system with
overlapping communities with differentt access rights
- comparisons with Darcs
- hg hosting, large projects, user support
It seems that hg scales to very large projects, as long as they're fairly uniform, but it doesn't support the sort of tangly fractal web of inter-project dependencies that would make it the holy grail of version control systems.