Rhonin and the two Archmages in the Citadel all seem to be wearing recolors of the supposed Mage Tier 7 that cropped up awhile back, so we can all consider that a definite confirmation. It looks pretty cool, if a bit unusual (wow, a tunic and not a robe!), with the helm turned off. With the helm on, I really couldn't help but giggle. You can see Rhonin and Vereesa above, and we've also added higher resolution images to our Dalaran gallery. Oh, and forgive the poor lighting. They apparently haven't turned on the electricity in the Citadel yet.
Gallery: Wrath of the Lich King: Dalaran