sent me this link: http://community.livejournal.com/changelog/10368879.html
It seems that LJ will allow identity accounts (OpenID, FB, Twitter, Mail.ru, Vkontakte, etc) to post in communities. It's not clear when this change will go live, or how far they are along in working on the feature.
In my opinion, this is a great idea, and is a major step towards making LJ more interoperable. As detailed in my post on LJ's marketing towards advertisers, LJ is really emphasizing communities as perhaps the central part of LJ. Making it possible for people to post on comms without going through the registration process makes sense, because now they don't have to remember another login/pw combo as well.
Anyway, I think this is all part of the "message-board-ization" of LJ. People who complain about LJ becoming like Facebook, I think, have got it wrong, because LJ has essentially renounced any ambitions to competing in the real-world social graph field. Instead they tout their site as being centered around common interests, and connections between people who don't know each other IRL.
IIRC, this is a feature which has been talked about on Dreamwidth, although I'm not sure whether it has been planned for implementation, or if it has, how far it is from being implemented.
Also, not directly related, but total agreement here: http://helens78.dreamwidth.org/1022248.html
I'd like for both LJ and DW to implement this feature. I already find it useful on Tumblr and Twitter.