Facebook has stated on numerous occasions that they want to be a central ID authority, so the article is less speculation than simply extending the Facebook game plan to the next rung. I currently recommend my site users sign in through Facebook due to the depth of their instant personalization features, but may offer Twitter or other access as well in order to calm users who may rightfully fear a company that does not respect anonymous speech. Even though I like Facebook's features and respect their technology, I must hear my customers concerns first.