Today is Reasonable Post Day, so I say, keep fear alive!
That's right, with the rumored return of crowd control in Cataclysm, fear may again become a useful spell in instances. I want to talk about fear.
Way back when back when I played a warlock, and then a warlock. I learned to use fear safely and productively. It's not as simple as other CCs which tend to involve clicking the mob and then it stays more or less in the same place. Not fear, that makes mobs run all over the place. So it needs some care.
For the warlock: Try to keep the mob back away from future pulls. This minimizes the chance that it will run into and aggro more packs. Try to even move to a different room, as the doorway can help to restrict movement toward the uncleared portions of the instance. Having some sort of timer for fear can also be helpful, as well as a focus macro, in order to quickly notice early breaks.
For the group: A properly feared mob can be kept busy indefinitely, so there's no rush to kill it. Focus instead on mobs which cannot be re-CCed, such as sap, or which are easy to break by accident and hard to re-CC, such as repentance. Sheep are a rather safe CC since it can be reapplied and doesn't cause much wander. In other words: Keep Fear Alive.
But it would not be reasonable to single out fear as the only CC that we as players need to adjust to. All long-duration CCs are vulnerable to damage. Even fear can break early if attacked too soon, but most will break instantly and automatically, and as I said before, repentance is particularly risky to break early due to the cooldown being the same as the duration. This means that attacks which deal area of affect or multi-target damage should be used carefully. A total prohibition isn't called for, but know where your damage is going and be careful when placing a blizzard or explosive trap.
With a bit of adaptation I think we can have an enjoyable time in the coming World of Warcraft expansion. We won't all love every aspect of it, but I expect a lot of people to enjoy many aspects of it.
Thank you, and have a reasonable day.