Thanks to Theymos, we have a completely new area to talk about the forum software that is being developed. Keep in mind that the code will be created for bitcointalk.org first but will serve as general purpose forum software under the MIT license once we have it delivered and in Alpha/Beta status. Let's start off with a temperature check...
Here are a bunch of questions and topics for everyone to discuss. Please keep the conversation going, keep trolling to a minimum and before you post, please ask yourself if your post contributes to the overall goal of creating this new forum software.
1. What are the existing problems (for you) with SMF and the current state of the forum? Please list as many as you can and feel free to elaborate on the issue.
2. What are the existing features that you would want to keep? Please do not be concerned about how petty it may seem as your opinion is valuable no matter what the feature is.
3. What would you like to see added that's currently not implemented in the forum?
4. Compare and contrast vs other platforms and their features. Would they work well with these forums? Take a look at Reddit, Discourse, Hacker News, Slashdot, Disqus, Facebook, Twitter, etc etc...
The goal is to create a compelling platform that can be used for notable/historical events while keeping useless content out of the way for the consumer.
-Slickage
Okay, I'll freely admit that I'm biased, but here are my suggestions.
1) The trust system that exists with SMF is a really bad idea. It makes it easier for people like TradeFortress to scam people over the long haul. Please make sure that the new forum software does not have this system, I really think it is a bad idea, especially with the default trust list.
Also, the bb code has a (fairly minor) flaw that I noticed a while back: I was trying to link to a URL that's https, and it wouldn't let me. It worked when I changed the url to be http format, but I couldn't do it with the SSL formatted link. I think this is a flaw, and while relatively minor, it'd be nice to not have to deal with it.
2) Obviously, as I'm using the quote feature with SMF, I like this feature. I think it's useful and makes it easier to reply to people's comments.
3) I'm going to second Cyrus's "Mark as spam" recommendation. Also, I think a better forum search option would be useful. Oh, and the one thing that may be useful that other forums have: a threaded reply option, where replies show up indented to the the post being replied to. Sort of in the reddit style, I guess? The one downside to this, however, is that if there are a lot of replies, the 10th or so reply gets really hard to read, so...I can do without it too.
4) Don't emulate Facebook features, they tend to make their UI worse over time. Disqus is even worse, I think it doesn't even work in Firefox any more, lately. (Unless it's my Adblock that broke it, but the rest of the internet looks fine, so I'm inclined to blame Disqus.)