I just had this work performed at 34,300 miles. Toyota paid to replace rear pads, turn rotors (if I'd waited until 35,000 miles I suspect rotors might have been replaced). I can't find out anything more about this TSB, except that it seems to apply to 2010-2011 Prius, and relates to uneven brake wear. Anyone with more information?
You can go to ToyotaTechInfo and pay $15 for a 2 day subscription. There you can find a complete listing of the TSB's for your car with full details.