45-46% of doctors will quit if Obamacare passes

That's what they said last August, and that's what they are saying now. Excerpt from Medicus:

Do physicians feel that health reform is necessary? The survey indicates that doctors do want change. Only a very small portion of respondents — about four percent — feel that no reform is needed. However, only 28.7 percent of physicians responded in favor of a public option as part of health reform. Additionally, an overwhelming 63 percent of physicians prefer a more gradual, targeted approach to health reform, as opposed to one sweeping overhaul. Primary care, which is already experiencing significant shortages by many accounts, could stand to be the most affected, based on the survey. About 25 percent of respondents were primary care physicians (defined as internal medicine and family medicine in this case), and of those, 46 percent indicated that they would leave medicine — or try to leave medicine — as a result of health reform.

Source.