I truly do not know how many average people can “adjust their savings” by $5K or $10K or more a year, without losing their ability to save entirely. I listen to Dave Ramsey and a lot of people live from paycheck to paycheck. The idea of having to stop or even raid retirement savings (what's left after 50% loss in 08/09) to pay income tax bills is frightening, especially since there is no more reliable stock market to invets in, and no real estate appreciation to provide a future source of wealth to draw from in retirement.
That is where I worry. And if people like me are worried about coming up with thousands more in taxes (we already did this past year with the AMT) then a lot of people could be in big trouble.