One warning - not to derail the discussion, which is amazing - I'm as sure as is reasonably possible that at least one major search engine used META keywords as a spam signal in the past, and I'd bet it's still corroborating evidence for Google. Probably goes without saying, but if you use it - use it well. Just because it's not a positive ranking factor doesn't mean it's not a negative ranking factor.

I agree that the competitor aspect never bothered me. Hopefully, you also use your keywords in your actual content. Otherwise, what's the point?

That's the kind of study I don't do because I'm secretly afraid it might work and then I'd have to quit my job and just drink full-time.

If it's just a matter of link count, I wouldn't worry about it. If the comments are clearly spammy, then I htink M.-J. is exactly right - you need to moderate and remove those comments. It is possible for a large number of spammy comments (with outbound links) to cause problems with a site. It's not just an SEO issue - it looks bad to legitimate visitors as well. If you can't moderate, nofollow would be the next best option (the only other option, really).

If you've got 200 links on the page, though, and the comments are 95% legitimate, it's fine. It's just a popular post.

Honestly, submit and forget it. You could wait months, and I don't know of any secret way. If you're following the DMOZ rules, then no submission service is really going to help. In many cases, there just aren't enough editors.

The other issue is that many new DMOZ links are on deep pages, some of which aren't even getting indexed. No indexation means no link-juice. See my blog post from last year:

http://www.seomoz.org/blog/wheres-the-love-dmoz

At the end of the day, it's just one link. It's nice to have, but your efforts are better spent elsewhere, IMO.