Compare and Contrast DVCS Tools (primarily git and mercurial)

Plan is to do a very short short (10 minutes?) centralized vs. distributed overview and then probably do an outline of some of the main different DVCS approaches. Then we'll do a deep dive into the subtle differences between git & mercurial. (How branching is subtly different between the two, why reflog is amazing, how subrepos are handled differently, rebase vs. merge, etc.) I'm sure we'll discuss the different commandline and graphical user interface options for each as well at some point. :)