Many of these lists do work ok, such as the Web Designer's Forum . No traditional list momming in the sense of reminding people not to quote multi-layers of messages, yet best not to disagree with him either. I prefer mailing lists over other formats, though they also have their merits. The disadvantage of lists, though, is that you have to hang around a bit to get used to the atmosphere and figure out the unwritten rules. While with the comment format, you can kind of jump in any time.
Forums are somewhere in between the list and the weblog.
The interface of a forum can do a lot to influence how much organic interchange takes place too. But the rather sad fact is that for a civilized online exchange, some form of censorship is needed. There is no point at all to this rambling, but I am and have always been fascinated by online communities. Now back to work. Very interesting reaction to design theft.