The employer’s matching tax for SS was never dropped, so it shouldn’t “go back up”. The only increase will be that the cutoff will go up a bit for 2013, in line with inflation.
Since you are an employer, you should have known that, since you have been paying the 6.2% employer SS tax for the past two years, not the 4.2% employee SS tax.
I use a payroll service and am only passing on what was told to me. I will be the first one to dance a happy kazatski if it turns out to be an overstatement. The paperwork for the first payroll of 2013 will come through later today or Monday.