The version control hoster that we use has an integrated ticketing/bug tracking solution, which lets you easily reference tickets in your commits to do this sort of task updating.
We don't make huge use of it, since we've only got about four developers, so communication is pretty easy, but it can be helpful.
Ours does too. I find that it is nice to have the additional information when the commit message is a bit general. Although this is a problem with the message itself.
It also can be helpful months later when needing a reminder why something was changed based on an assumed unimportant detail at the time.
We don't make huge use of it, since we've only got about four developers, so communication is pretty easy, but it can be helpful.