Obama's tax plan, according to this article, would raise the marginal rate on the self-employed who earn more than 250K to 53%, including income and social security taxes (taxes would be lower for employees, but their wages will be reduced because their employers will have to pay half of the social security tax increase). The marginal state and local rate for residents of New York City is around 11.5%, which will likely not be deductible for federal purposes because of the AMT. I'm not sure exactly how the AMT fits into this (does anyone really understand the AMT?), but figure the top marginal tax rates for residents of NYC, DC, California, and similar high tax areas will be 60% or higher. Yikes!
I expect that attorneys, physicians, and other high earners are going to be negotiating for less income and more non-taxable compensation (reimbursement for continuing education vacation boondoggles, more money to pensions, and so forth), rather than submit to having most of their income siphoned off by the government.
I remember reading a few years back that the majority of Americans don't think that anyone should pay more than 1/3 of his income in taxes. A campaign issue for John McCain?