However, a surprise to me is my federal tax withholding went up quite a bit. I called my job's finance person and I was told that the 2013 tax withholding's tables increased the amount of taxes withheld across all rates.

I suggest rather than donning your foil hat and going on black helicopter watch you wait for the dust to settle. It's been barely 2 weeks since this year's tax rates were determined, which is certainly not enough time for payroll software to have been rewritten. If it was based on existing law before 1/1/2013 it's probably accurate for that scheduled tax increase. As the IRS is able to get revised tables and guidance out to the payroll community there may be adjustments prescirbed. Once your withholding has stabilized at the new rates you can see whether you need to adjust your W-4 for the remainder of the year.

Also, if your annual wage is more than $200,000 you're subject to a Medicare surtax, which will be shown as additional income tax withheld, starting 1/1/2013.

Phil
Rule Your Retirement Home Fool