IMHO it'd be excellent if syndication were built into the LJ server. If someone has a site they'd like to syndicate, they should be able to hit a page, type in a suggested username, the URL of the RDF/RSS feed, and have that feed get syndicated under that username. No central administration needed, no dependencies on outside systems.
This doesn't seem like a huge project. Maintain a syndication table on the server with all the data, a couple of BML pages to create and maintain syndicated accounts, and an ljmaint script (possibly derived from piman's scripts) to suck the feeds and create entries.