While Facebook continues to receive complaints from users on the site redesign (the “Petition Against the New Facebook” group has grown from 400,000 users on Saturday to nearly 1 million users tonight), many users have already switched over fully to the new version.
In the meantime, Facebook Platform application developers will have to support users of both the old and new versions of the site for several more weeks.
Source: http://www.insidefacebook.com/

