Well I still maintain that, unless the opponent has a fast scarfer / setup sweeper already in, QD Chandelure will be a threat. Besides, Volcarona has already been established to be a good defensive Pokemon even in standard OU, but what does that matter when the idea with QD chandelure is to be a deadly sweeper capable of OHKOing Pokemon after Pokemon?
Quite frankly though Gluttony Snorlax terrifies me the most of what I've noticed so far, with that Belly Drum / XSpeed combo and access to great coverage in Crunch and Earthquake / Brick Break. Gluttony also is useful on the set - for either a healing berry to preserve Lax's good bulk, or to use a coverage move in conjunction with Custap Berry to outspeed the predicted XSpeed-resist switch-in and hit them with the coverage move of choice, before sweeping the rest of the team with XSpeed.
Compoundeyes Galvantula gets Sleep Powder and Stun Spore (thanks to Butterfree) and thus can go with a deadly-accurate double-powder set along with its powerful STAB Thunder and Bug Buzz, or forgo stun spore for a coverage move. Oh yeah, and it also gets Quiver Dance.
One of my favourites that I've seen is Tinted Lens Yanmega, who thanks to Venomoth now gets Sleep Powder and Quiver Dance to use in conjunction with its fantastic ability, good stats and great dual STABs. In just two moves it has perfect coverage, and a combination of Sleep Powder and Quiver Dance means it can shut down the switch-in and boost until almost nothing can wall it. Even Blissey would have trouble with this, and remember that both Magic Bouncers are at least 2HKOed by a +1 Bug Buzz.
Prankster Sableye gets Leech Seed from Whimsicott - say goodbye to any and all possibility of full stall being viable :P Oh, and it also nabbed Tail Glow and Baton Pass from Volbeat, so go ahead and use that combo on this far superior Pokemon.