Does anyone know exactly how this works?
Does it up-scale gear as well as down-scaling it?
Does it scale gear based on the stats the gear has? (EDIT: That is, if I've reforged heavily into haste, am I going to keep that relative advantage compared to crit/mastery)
Does it affect hit/expertise; if I'm exactly hit/expertise capped for heroics in iLevel 500 gear, is it going to under-cap me when it scales me back to 463 or whatever iLevel to which it scales?