A few different folks have heard me mention the SPAM-L mailing list in conversation these past few months, and expressed surprise; thinking it had been retired. The old SPAM-L mailing list was indeed shut down back in May, 2009, but the list was almost immediately resurrected by J.A. Terranson and a few other kind folks. It now lives over at spam-l.com, click here to learn more about the list or to subscribe.
The new list is very similar to the old one; it's a bit of a collaborative free-for-all wherein all interested parties in the spam stopping equation can share information, experiences, and even a bit of best practice guidance. You'll find folks on both sides of the email sending and receiving equation, and maybe a representative of an ISP or blacklist or two.
The new list moms have made it clear that collegial behavior is a requirement for participation, that means if you go in their with guns blazing and gums flapping, you're likely to find your posting ability restricted or moderated. Overall, I suspect that this is probably a good thing, as it's caused people to have to think before they speak.