With the 2013 change permitting 401k conversions to Roth 401k does this change the pro rata calculation for IRA to Roth IRA conversions?

No.

There seems to be some confusion about this provision. In-plan "conversions" to Roth have been allowed previously. This is just housekeeping to make them easier, thus, in theory, more attractive so that people will flock to them, thus producing the revenue necessary to "pay" for kicking the sequestration can 2 months down the road.

Nothing of note to the employee has changed in the law.

Phil
Rule Your Retirement Home Fool