Warren Buffet told Congress that billionaires like him should pay higher taxes. Strikes me that he is free to chip in a billion here or there if he feels the need, but I don't think that he has been appointed to speak for other billionaires.
But Buffet is both right and wrong. He's wrong when he says the tax rate should be raised for wealthier Americans. He's right when he says the government should get rid of all the tax breaks. Just make sure that everyone (and every business) is treated the same. No big exemptions, deductions, subsidies and so forth for big oil and for middle income families. That would raise revenues dramatically by broadening the tax base and ending the scandal of the wealthiest paying few or no taxes.