you need to react to something in a hurry
The simple fact is that the constant, passive ability to perform a complete DPS rotation while moving was never intended to be a core feature of the Warlock class. Those who remember the early days of Patch 5.0 will recall that, initially, Kil’Jaeden’s Cunning actually increased cast time whenever it was triggered. In those days, that extra cast time made the talent so unattractive that very few players actually took it. We decided to try it as only a snare instead, but that has had the opposite effect: in Patch 5.3, virtually all Affliction Warlocks are using Kil’Jaeden’s Cunning. Remember, we want talents to be meaningful choices. If one talent is far and away superior to its neighbors, there’s a problem. There were also some very strange side effects (such as the ability to cast something like Fear while ducking in and out of line of sight).
Now, as I mentioned, the ability to always cast on the move wasn’t intended as a core Warlock feature (otherwise, it wouldn’t have been a talent). However, that doesn’t mean we want Warlock DPS to plummet every time there’s a fire on the ground. One thing that may have gone under the radar is the fact that the new version of KJC is not on the global cooldown, and can be cast while another cast is already in process. So, for wow or example, you won’t have to interrupt a Chaos Bolt to activate KJC should you need to react to something in a hurry.
Furthermore, it’s a change that we’re certainly going to balance around. Remember, we’re very early in what is likely to be a lengthy PTR cycle. There’s plenty of time to tweak and tinker with it. In fact, a recent change made internally allows Haunt to be cast while moving by default. The goal is most certainly not that Warlocks lose out on a ton of DPS or lose viability in raid encounters. We do encourage you to hop on the PTR, experiment with it, and tell us what think once you’ve gotten some hands-on time!
