At an anonymous moderator's behest, my suggestion:
Moderation should be completely separate from users' personal accounts - that is, Beleth/Karyn/pandamonium/Louie/DRmeg378/TLV should simply be user accounts. A new account (say: Moderator) could be created which would handle all moderator related actions, or the actions could all be anonymous and the new account used only for moderator posts such as the letter posted above. This would (hopefully) have the effect of removing the extra weight which may be perceived to come with any post from a moderator, and to separate the opinions of "the mods" from that of the individual moderators.
Of course, implementing this now when most people know who the mods are might not have a huge impact, but if I was designing a forum from scratch, this is how I would start. Even having a single voice might remove allegations of individual bias from particular moderators.