In 4.3, we fixed a bug where Deep Wounds was benefiting from the 40% auto attack bonus from Precision. Deep Wounds should only be triggered by crits, not passive damage.
We also found a bug introduced in 4.3 (and reported by several players) that Deep Wounds was not triggered by attacks such as Heroic Leap, Intercept and most importantly, Raging Blow. We are deploying a hotfix to fix that bug.
Deep Wounds should not benefit from spell enchants, such as Avalanche. In general, enchant procs should not have synergistic effects with talents or class mechanics.
From what we have seen so far, Fury’s damage is still where we want it to be in 4.3. We will see how things change as more data comes in. If we think Fury’s damage needs to increase through Deep Wounds or some other mechanic, we will be sure to do so.
We can indeed confirm that if you're getting loot from of a boss twice then it is an exploit.
This has always been the case in World of Warcraft, and we expect players to know better.
We’re in the process of implementing a hotfix to fix the exploit, and are deciding what steps we'll be taking for the gear that was already obtained.