You all make it sound like the tax rate above $250k (net profit, after expenses and payroll and deductions) would be incredibly different. The difference is between 36% and 39%. If you count in the small business breaks that Obama provides, and the <$250k shield, your business would have to make probably closer to $350k per year in NET PROFIT (that's after you pay yourself whatever salary you want, and pay all your employees, and pay all your expenses, and take all your deductions), before McCain's stance would save you anything.
If you're at that point, then you're doing several million dollars gross in business per year, you're probably making however much money you want to make (in salary), and you STILL have that much net profit. If you're doing that well, I think that difference between 36% and 39% is not unreasonable. That's only an extra $3000 in taxes per HUNDRED GRAND in net profit, and again, that's after you pay yourself whatever the hell you want for a salary.
50% of all companies have paid zero dollars in taxes for the last seven years. Those that have paid taxes are the top of the heap -- Exxon, Microsoft, Google, etc. I think they can handle it okay without shifting their tax burden to the middle class, which can't.