Little question regardless actual specialization

Haven't play recently on Cata for like 3 months+, I heard Assassination is at the moment best spec (I saw Venomous Wounds bugtracker).
So do you go any specific stats priority? What about the Hit rating? And if possible, tell me what is actual reachable DPS on specific Dragon Soul bosses?

everything is same as 3 months ago

Even at 378item level, you can easily pull 30k on ultraxion, going toe to toe with people at 390ilvl quite easily.PS: Equip Glyph of Vendetta over Backstab for that fight.