Patch 2.4 has arrived! Hurray! Many things have changed, some minor, some major. It will take time to assess the long term impact of these changes, but what everyone wants to know right now is "What changed for MY character?".
Unfortunately for the rest of us, there is no big nerf to warlocks in PvP, the life tap ability change was removed from the patch. Overall Warlocks (like Hunters) do not see any big changes. The only really big change is that they can now summon players into instances as long as that player meets the entrance requirements for that instance. This is a change that will have many players (not just Warlocks) cheering.