See Cracking Facebook's Dominance: New Cross-Network Commenting Protocol Could Be a Game Changer.
Am all for cracking dominance, Facebook's or otherwise. It is mindboggling that 400 million people needed a new version of AOL to enjoy the web. From that article, this sounds so weak:
Simply put, if you could leave Facebook and still communicate with people using Facebook (you can't today) then leaving Facebook would be a lot easier, and more social networks would have reason to invest in building a compelling service for you to use. If there was more than one meaningful option, those services would compete to build the best social network they possibly could. And Facebook would have more reason to be careful when considering dramatic changes in things like its privacy policy. Today, where else are you going to go without losing touch with all your friends?
You can pretty much find anyone with a few seconds' diligent googling. Why is being in instant, annoyingly close "poke" range of everyone you ever knew from the date of your birth to the present so important to people? I don't get it. (Obviously I am not on Facebook.)