So I picked up Abracadaver the other night to play with for a shadow offspec... Curious about the 'use', I went to the nearest training dummy only to find out that the Cadaver will only 'protect' you if you're attacked (aggro), and will not go on offensive.
I went down to Crystalsong, aggro'd a lvl 78 Sinewy Wolf, shielded myself and triggered the use, anticipating the bloodbath to follow as my evil minion tore through the beast, unleashing his rage after being cooped up in a 15 minute cooldown!
60 dps. For one minute, or until he dies. Hey that's not bad... If I use it every CD it could be good for a whopping 4 dps!
Ok, I gotta admit I like the staff, love the name, and the use is pretty cool, but seriously... Couldn't they have given it something closer to shadowfiend dps? If you're weighing the value of the use into your comparison of this staff to other weapon options, well, just don't expect a lot.