Now that the WMF has Google Chat (their answer to Slack and their evolution of Hangouts) we should consider building a bot that pushed updates from Phabricator tickets (scoped to project/tag) to Chat. This would be much like the wikibugs bot in IRC.
Since everything in Google Chat is a thread, a task should get it's own thread (if one doesn't exist) and then a new message for each "action" under that thread.
The bot should work with any instance of Phabricator (via configuration)
It might also be helpful if the Phabricator bot could accept certain commands (like creating a new task, etc.)