The plugin was built by Facebook engineers in collaboration with open source partners, and makes it simple for anyone to make their WordPress site more social – no coding required. The plugin will also work on mobile and support internationalization.
Talk about being behind the times. You already could do all that. There are any number if plugins and services that do exactly this, and some have been around for years now. I've tried a couple plugins, and right now I'm using the free service dlvr.it to post Facebook updates.
But let's put the snide comments aside. This plugin is worth a look because it quite simply offers more options than most of its alternatives, including the ability to add a custom lead comment as well as the ability to post to other people's timelines and more.
The dlvr.it service doesn't offer nearly as many tricks as this official plugin; all it can do is post a simple blurb. The competing plugins aren't very good either; I've tried several and they ranged from acceptable to horrible. The best unofficial Facebook plugin was also extremely buggy; it broke down on a weekly basis.
Yes, I'm definitely adding this to my to do list for the weekend.