I don't understand how this new privacy policy is gonna affect social bookmarking...?? I think you are posting this question in context of history and all that stuff... But just to tell you that Social bookmarking has nothing to do with history of the user.
I agree with Jameshoriton, social bookmarking is still useful since it's one of the best strategies to promote your websites in the search engines. It helps you increase your search engine rankings, Google page rank and increase organic search traffic.
Social Bookmarking was never affected by Privacy Policy and neither it should. Its serving amazingly to websites.
Could I turn this around and ask you what there is in the privacy policy that leads you to ask the question?
Social Bookmarking is still effective no matter how the privacy policy is take effect. It was useful in link building in order to target traffics and get backlinks.