For example, say if I started employment while I was single, so when I filled out tax info for my employer when I started, it reflected that I was single. Being single I would be in the 25% bracket. Later that year if I got married and my wife didn't have a job I would drop down to 15% so that when I actually filed my taxes I would be in the 15%. Being that the paperwork I filled out for my employer probably indicates that I am in the 25% bracket wouldn't they be withholding too much thus resulting in money being returned to me after I finish filing my taxes?
Are you saying that you did not tell your employer, more specifically, your payroll department, that you got married, via a W4?
The W4 does not say '25%' bracket, but it asks for how many withholding allowances you plan to take. In effect, you are withholding at the single rate, but are married now. When you do your taxes for 2013, you'll see the full effect of what the W4 has on your withholding.
I suggest you use this time to update the W4, and not lend money to Uncle Sam.
Here's the current tax table from FairMark Publishing. 2013 gives a single a combined $10K in standard deduction and exemption, with a couple getting $20K. For a simple return, this is the info you need to figure out what you'll get back, and conversely, how much to pay next year.
e.g. a gross of $50,000 - for single the tax is on $40,000. $5929. For a couple, $30K taxable is a tax of $3608.
On a side note - I strongly recommend Roth accounts when in the 15% bracket and shift to Pre-Tax accounts as you get into the 25% bracket.