Oh god, revsets. When i was able to use Mercurial (via hgsubversion and hg-git), i used revsets constantly, to ferret out all sorts of useful knowledge from the repository. My Git-using colleagues thought i was some kind of wizard. I switched jobs, and now i just use Git. I miss revsets so much.
In that lightning talk, were you actually typing or were you playing an accelerated recording of you typing previously? Cause it seems like you type at something like 300 wpm or something insane like that!
* revsets -- feature-rich DSL for querying your history, my presentation on them:
https://www.youtube.com/watch?feature=player_embedded&v=NSLv...
* templates -- the output of just about any hg command can be customised:
http://mercurial.selenic.com/wiki/GenericTemplatingPlan
http://jordi.inversethought.com/blog/customising-mercurial-l...
* Evolve -- safely rewrite commits as a team, a safe replacement for `git push --force`:
https://www.youtube.com/watch?v=4OlDm3akbqg
* Very easy to write extensions:
http://mercurial.selenic.com/wiki/UsingExtensions
* Mercurial scales well to gigantic monolithic repos:
https://code.facebook.com/posts/218678814984400/scaling-merc...
That's all I can think of for now.