It's being replaced with Touch of the Grave, an ability that appears to be an on-hit proc that leeches health from your enemy. The spell description is as follows: "Your attacks and damaging spells have a chance to drain the target, dealing 12654 to 14706 Shadow damage and healing you for the same amount."
We imagine the damage done by this passive will scale by level, a level 10 undead rogue won't be draining 14,000 health from their enemies in Warsong Gulch. Still, it's pretty awesome, right? We think so.
It's open warfare between Alliance and Horde in Mists of Pandaria, World of Warcraft's next expansion. Jump into five new levels with new talents and class mechanics, try the new monk class, and create a pandaren character to ally with either Horde or Alliance. Look for expansion basics in our Mists FAQ, or dig into our spring press event coverage for more details!