I think that promising the same experience for both console might be the biggest problem with console equality, yes ps3 owners were entitled to a better version of ff13 butgiven the for example bayonnetta was supposed to be developped on 360itsomehow deserves to run better on 360.
But if you want games to be better or equal on the ps3, then tell everyone you know to buy one then devs will have more interests in developing them first.