What I'd like to see is a moderated and unmoderated version of the same list, or at least a publicly accessible archive of all posts to the list moderated or unmoderated. That way those who want the "raw" stream could get it, and anybody who cared could track exactly what the moderators are doing.
I think this shouldn't be very hard if you can send all rejected posts to another list. Anybody who want's to could sign up for that list too.
Even better would be for all posts to the unmoderated list to be forwarded to a moderated list for approval. Then those who want the raw list don't have to wait for the moderators to get involved.
Probably what should happen is that all rejected posts receive a message saying that if they want to appeal, to forward the post to an alias, which goes to all the moderators plus me. Also good would be for all rejected posts to go separately to all the moderators plus me, thus inducing some peer pressure for moderators to do the right thing.