I also like the powerful revision querying mechanisms that they pulled in from mercurial. They seem to work just like mercurial revset queries which can be used in various operations on sets of revisions.

I would like them to have mercurial's awesome hg fa --deleted when it comes to history trawling, but apparently for it to work well, they also need to swap out git's diff format for mercurial's smarter one, so I'll be waiting on that for a while I suppose.