Hmmm. Little concrete information, but this is one of the few times that a Blizz dev has openly acknowledged just how powerful certain classes are in relation to others. While they've made no secret of the fact that they don't balance PvP around 1v1 battles, and admitted at BlizzCon that warlocks are essentially the best dueling class, it's still unusual to see official commentary on specific class rivalries.
And, let's face it, the Mage versus Warlock smackdown is practically the stuff of legend. With these tidbits appearing on the forums about class and talent changes in Wrath, keep checking back; we're likely to hear about more of these soon.