You're right. I'll tell what I know. A proper general announcement would be better, of course, but it's not within my power to speak for the government of LW. I just PM'd Eliezer asking for such an announcement to be made.

Some days ago I got a surprise PM from user matt saying I'd been made a moderator. As far as I know, everyone on the "top contributors" list except Roko got such messages. My only superpower is deleting ("banning") posts and comments, and it's meant to be used only for removing spam. I cannot promote posts to the frontpage or ban people. I have not exercised my power yet because there was no need. Lists of moderators are at the following URLs: mods for LW proper, mods for discussion section. I don't know if non-mods can see these lists, so I'll retype them here.

LW: Eliezer_Yudkowsky, RobinHanson, AnnaSalamon, Yvain, Alicorn, Kaj_Sotala, PhilGoetz, Wei_Dai, cousin_it, Vladimir_Nesov, Kevin

Discussion section: wmoore, AnnaSalamon, Eliezer_Yudkowsky, Yvain, Alicorn, Kaj_Sotala, PhilGoetz, Wei_Dai, cousin_it, Vladimir_Nesov, Kevin

It goes without saying that if there's ever any significant controversy about my "banning" anything (though I find that hard to imagine), I'll give up my mod status.