The 60,000 page tax code itself is the issue, not another tweak or incentive in the way of tax rates, credits, deductions, or what not. The uber rich (including Warren B and Bill G) pay VERY LITTLE as it stands now because of how the code protects those who have concentrated, inherited, or sudden wealth. For just one example, just set up a qualified multigenerational family foundation, put a big chunk of appreciated stock in it, and you avoid the majority of capital gains, income, and even estate tax - forever! The world of trusts and foundations is murky to most people, and the truly rich (as opposed to very high income workers/business owners - VERY different people) depend on your ignorance of how the code really works to perpetuate class warfare that in the end will leave them right where they are. Yes, it's the new American Aristocracy.
The only real answer to spur the economy and solve the deficit at the same time is a true flat tax with no or extremely limited deductions, with the first $40K (or whatever a living wage is) non-taxable for everyone.
Fair? Yes. Progressive versus what actually exists in practice today? Absolutely.
I laughed and cried when I read of Warren Buffett's recent plea to raise income tax rates for the super rich. I'm not sure Warren would like a truly flat tax as it would actually touch him. Put another way, raising the top bracket to 50% or so still wouldn't really affect him, since his 'income' is for the most part sheltered and never shows. Do the math with me - WB's $6.7M tax bill last year divided by his liquid net worth works out to about .1%, not the 'only 17%' (?!) of his income that he claims in his op-ed. Most of his net worth has not been and will not ever be taxed under the current code. Buffett's statements about the rich paying their fair share yesterday were intellectually dishonest in my opinion.
Read this classic if you actually want to be informed on this issue - they've covered all the objections you can think of, and more. Anything that Jerry Brown and Ronald Reagan agreed on might be worth a look.
Now, if only someone somewhere had the charisma and political will to actually pull such a thing off, given that legions of lobbyists, CPAs, bankers, investment advisors, etc. etc. etc. would do everything they could possibly do to kill any such reform since it would negatively affect their businesses.