The Heritage Foundation lists 13 tax increases for the new year 2013. See 13 Tax Increases in 2013.
The item that will affect the most people is
Payroll tax: increase in the Social Security portion of the payroll tax from 4.2 percent to 6.2 percent for workers. This hits all Americans earning a paycheck—not just the “wealthy.” For example, The Wall Street Journal calculated that the “typical U.S. family earning $50,000 a year” will lose “an annual income boost of $1,000.”