Given the major Keep update to v2 today, I got excited when I saw that Hangouts was updated as well a short time after. Unfortunately, it seems like it's a very minor bump: from 220.127.116.113199 to 18.104.22.1688356.
A quick teardown revealed updated translations and some minor under-the-hood code changes that aren't anything to write home about. The changelog hasn't been updated either and still lists the added emoji support and other stuff from the previous v1.1 update. I doubt Google will update it at all for today's release.
The update is staged, as always, but if you really want it ASAP, you can grab the verified APK from our mirror.
Thanks, Matthew Garbett and Mobilephonesfan!