Now, Neth says that the reason DHKs are out is because the devs tried leaving them out, and apparently it worked on the test realms. Some NPC levels have been raised, and some have been lowered, so there may be other incentive in game to keep people from mauling, say, Crossroads on a regular basis. Also, there are some new World PVP options in the works-- don't count those out. But Neth also says that things are constantly being monitored-- if city raids become an issue, the situation will be revisited. As a few players point out, however, (and I agree), the test realm players aren't the day-to-day players. People will do almost anything in this game, so I expect raids to show up on a pretty regular basis, even on PVE servers.
Not that you need to get rid of DHKs to do a massive raid. MBAzeroth reports that the Penny Arcade Alliance (named after the comic, duh) on the Dark Iron server pulled off a big one. Alliance coordinated and invaded the capital cities while running distraction raids on Brill, Tarren Mill, and Crossroads. The casualty list is shocking: Cairne, Thrall, Vol'jin, Varimathas, and almost Sylvanas before the server got downed by the raid. Now that's some good World PVP. Are we looking at something like this every week when DHKs go bye-bye? One can only hope.