You've traversed the wilds of Pandaria. Your mage has decked himself out in shiny new quest reward greens that are better than the purples he farmed Deathwing for months to collect. You've killed X number of mobs, collected X number of inexplicably difficult-to-locate vital organs from those mobs and returned them to people with increasingly tough-to-reconcile reasons to want said organs, killing a potentially genocidal percentage of the warlock population along the way. Now, you're level 90.
Your reward is two new abilities. One is Alter Time, which we've already discussed at length. The other is entirely up to you. There are three new choices in your talent ladder to select from. They range from a fresh and infinitely more useful version of Mana Shield to a crazily improved buff for Evocation to a rune of wizardly sparklesauce that you place on the ground and then set up shop there, serving up magical deathfire to all customers forevermore, amen.
They sound quite different, but have one thing in common: You press a button, and you get mana and spellpower. I think we can all agree this is a button we want. The question is, which of those three buttons do we want the most? And the next question is, do we want any of them as our capstone talent?