He's just quin-boxing it, the Best Man is solo-boxing as tank for the aggro from the Bridesmaids; the Priest/Minister is obviously healing, it's a raid not a 5man ;) Just make sure noone FDs during the vows and make SURE you mana tap before the wedding so you can cast Arcane Torrent when he asks anyone to speak now or forever hold their peace :P

Congrats ;p Gl with the new BoP debuff that lowers free time ;D