I've seen elsewhere potentially reliable estimates of 16 million policies being canceled out of a total of 18 million (the grandfathering is insanely strict).
This is also happening to the people who use Medicare Advantage, the HMO style alternative to the original Part B coverage, which is good for a variety of people, especially the urban and less healthy. Being terminated with extreme prejudice by 2016 as I recall, getting thoroughly squeezed starting next year with "you're going to have to chose another PCP" notices going out right now.