Quick hit here. After the debate, many bloggers wrote how Romney got away with not being specific with which deductions he would eliminate to make his rate cut be revenue neutral.
Well he just came out and said he wants to limit the total amount of deductions, which essentially gives taxpayers a choice of how they spend their money. You can still, for example, deduct mortgage interest (up to a certain amount), but that means you wouldn't be able to deduct for improvements to your home office. Or vice-versa.
That effectively flattens the tax code and does precisely what Mitt Romney says he'd do, which is to make his rate cuts (more or less) revenue neutral. Only a small portion of households actually itemize deductions (because for most families, the standard deduction is greater than the amount they can deduct otherwise) and an even smaller portion of households deduct a ton on their returns (the richest households).
This keeps in place our progressive income tax system while limiting the tricks that accountants can use to minimize a high income household's tax bill.