Probably the best driver of the golf ball on the planet, Mcilroy utilizes a free-flowing, powerful swing motion. At 5'8 and 160 pounds, he regularly flies his driver well over 300 yards. Mcilroy utilizes the ground and his body rotation better than just about anyone in the modern game.
He keeps his right arm in front of his chest for most of his backswing a la Tiger before dropping it in transition while squatting and rotating extremely aggressively. If you have problem with Tiger's "dipping," then you should have a BIG problem with the same issue for Mcilroy.