how exactly can they overhaul the tax code if they've just agreed to extend the 2001 and 2003 tax cuts for 2 years? any overhaul plan that includes even a small increase from those already too-low rates would be dead in the water before congress.
i guess maybe they could have the overhaul plan not go into effect until january 1, 2013, to assure technical compliance with obama's current 2-year extension deal. but i don't see the GOP going for that either because it would take away their next hostage scenario during the 2012 presidential election campaign.
the bottom line is a tax code overhaul, even if it's a good idea in the abstract, is not a serious plan if the president's deal with the GOP on extending the bush-era tax cuts goes through. the only scenario in which an overhaul might plausibly happen is if democrats in congress reject the deal and the tax cuts expire at the end of the year. only in that case would the GOP in the new majority be willing to seriously negotiate over a tax code overhaul next year.