We used to have Open Threads on this forum. I was hoping someone would bring them back. No one did. So now I'm the change I want to see in the world.
Use this thread to post things that are awesome, but not awesome enough to be full posts. This is also a great place to post if you don't have enough karma to post on the main forum.
Also Happy New Year!
I also think there is some demand for less-formal discussion here (such as in Open Threads, like you say) because of the current somewhat-low population at lesswrong.com.
I agree that a subreddit could fill this niche, however i am not aware of any currently existing subreddit for this.