So I guildie and I were talking before Naxx a while ago and ended up talking about Bonescythe 4 piece + Darkmantle 4 Piece. I proposed adding in 3/3 Vieled Shadows for the chance for +15 energy on SnD. Didn't have much time, but I played around with it some on ctprofiles. Seems you'd be really hurting for hitpoints, but otherwise the stats were about equal to a Rogue in Tier2/Tier2.5.
I can't get on Thottbot from work for some inexplicable reason, so I have no idea what the proc rate is on 4 piece Darkmantle. I doubt it's particularly viable with how crappy most of the Darkmantle set is, but I find the topic interesting and was wondering how this gear set up would do in raids with CD. Someone bust out some pretty numbers.