I agree with wedrifid, and would prefer that this doesn't happen.
One problem is comments are "non-local", as long as they are above the bad-comment threshold, they appear in the recent comments. Allowing people to have stupid discussions freely will pollute the recent comments section (and this was actually one of the reasons for the recent implementation of the karma threshold).
If LW supported marking some threads as "comments don't appear in recent comments", then it wouldn't be such a problem, although there is also the risk that the low-quality will start overflowing into the rest of LW (maybe?).
Hmm. The non local nature of comments is a good point and one I had not considered. I had initially been thinking that this might be helpful to some, and that most folks (myself included) would opt out. Since everyone sees the recent comments I am now desuggesting my suggestion.
I have never been on a Lesswrong meetup because they tend to take place too far away from my range in terms of distance and budget. Because of that, I don't know if those perform this function to everyone's satisfaction in such a way that what I'm suggesting here doesn't seem worth the effort. I hear that they're a lot of fun, and involve quite a bit of silliness, though; I find those cruelly lacking on Lesswrong proper, whether it be in main posts or discussion posts, and their relevant threads.
That's why I think it would be nice to have a forum, a place to have normal discussions, where you don't have to watch that you don't say anything stupid or out-of-line lest you unexpectedly lose karma. A place to exchange jokes, frivolities, and entertainment. A place to talk about stuff that isn't rationality or singularity-related. A place to relax and enjoy the company of like-minded folks. A place to take a more personal approach to communication, with sequential rather than branching conversations. A place to make and be friends.
Don't you think having that would be nice?
EDIT: Also, if this place does already exist and I'm not aware of it, I humbly request that you provide me a link, for which I would be most grateful.