@Secret_Tunnel Well I didn't start any of this but I've experienced enough of it so I guess I can comment.
Our bar get-togethers don't always involve talking about what we're working on. Well, maybe sometimes. But really, I think a lot of developer don't WANT to talk about what they're working on all the time, especially if they haven't been making a whole lot of progress since the last get-together. Plus a lot of people just like coming to hang out and aren't openly working on anything at the moment. Really it's mostly just game dev people hanging at a bar, drinking, talking about whatever. What else do you need?!
We also have a more formal meet-up once every two months, usually held at a local university, that loosely follows the format of...
Phase 1. Developer talk (about an hour.) Sometimes we get some fairly big names for this, like when we had the Shovel Knight programmer come talk, or the Kentucky Route Zero team, or the Octodad team, etc. Other times smaller local names.
Phase 2. "Open mic". Basically anyone who wants can sign up to get 5 minutes to get up in front of the crowd and show off their game on the big screen. We usually get around 6-10 people / teams showing stuff off.
Phase 3. Open play / mingling. Anyone who wants can set their game up for open play / playtesting. This is also the point where people just hang out and talk. In fact sometimes there is a lot more talking than playing, but I still usually get a handful of people to try out my game when I decide to show it.
We have a lot more meet-ups, like a Unity specific meet-up where people show off specific Unity techniques and people can ask questions about how to do things in Unity. IGDA meet-ups. Game jams. Etc. Sometimes random stuff, like one dude just had a "work on your currently neglected game... jam" thingy at his house the other day and like 13 or 15 people or so showed up (mine wasn't currently neglected but I went anyway.) And obviously some big stuff like Bit Bash.
But yeah just getting people to hang out at a bar or whatever regularly would be a good start. And then if you have the community desire / space I'd try the dev talk / open mic / playtesting thing eventually, as being able to experience each other's games helps build a more community feel and personally, seeing all of this cool stuff people are doing keeps me motivated to keep at my own stuff.