Since getting better Facebook autoposting hasn't risen in the new feature voting and might take a while, if at all, I've written a plugin that does it.
Given a configuration of categories and facebook page or group IDs, it hooks to the onAfterSave of a post and then calls into the autoposting code to allow you to specify a different set of pages/groups on a per-category basis. I've got this completed and working on my site.
Before cleaning it up and making it available, I'd like to ask if anyone has any other features that might be useful for me to add. Given that I have this plugin working properly, is there any other kind of autoposting customization I can add that people would find useful?