I don't have a Facebook account, so I have no intention of using the feature.
Have to say I'm not keen on the way Apple is implementing third-party account support into OS X. It should be an optional module you can choose to install or disable, not a core OS feature.
If anyone has ever used Adobe's Lightroom, it should be something like that where there are built in publishing services for popular sites (Flickr etc.) but they can be disabled and disappear from the list when you do so, and people can create their own plugins if their sites aren't on the list.