Alright, I will provide you and everyone else with two tidbits of information that we've not yet revealed through any source. Both of which I'm personally very excited about, and hopefully you will be as well. First, when the Burning Crusade launches, healing over time (HoTs) spells such as Rejuvenation and Renew will stack for every player casting them. For instance, if there are three priests in your group, a target could potentially receive three renews as one time. Second, we're going to be scaling Warlock and Hunter pets come expansion so that they become stronger as the player gains more statistics through itemization.
This is both an incredibly overdue change and an exceptionally exciting change, given that my main in Azeroth is one of the afore mentioned classes, and my wife plays another (Ya, thats right guys, I married a girl gamer... Perhaphs if you stick around here long enough, I'll share the secrets of my success.)