I've had PZ_sav files appearing in at least PP2010. Not sure if it was a feature of Poser 8 and 7 ect... But I do have a few of them floating around so it's not a new thing to PP2012 :)

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.