Figure on a $500 contribution limit increase for most retirement plans, EXCEPT for IRA's. They will not be going up and they did not go up for the past couple of years. I'm guessing they'll go up by $500 in 2016.
The other exception to this is that contribution for HIGHLY COMPENSATED EMPLOYEES will be allowed to increase by $1,000. The overall trend here seems to be that they are allowing for increases with inflation. Which means that on average they'll let them go up by about 2% a year.