Did the PPA change how distributions must be made for an inherited IRA where the only beneficiary is a non-spouse beneficiary? I keep hearing that it did, but I can't find it.

PPA didn't change how distributions "must" be made. It did open up the possibility of a direct rollover from the QRP to an IRA taken in the name of the non-spouse beneficiary, as such of the deceased employee, as an alternate to other payout options in the QRP's documents. See Notice 2007-7 for some IRS Q&A on the topic. There was also a February 13 special Employee Benefits News from the IRS clarifying what the Q&A intended.