Talks about numbers.
Ignores the Instant Spammable 8 second fears elephant in the room.
I understand and share your concerns with giving warlocks another instant fear, but on the other hand MoP adds and changes a lot of abilities to all the other classes, and we can't think of any new spell independently from everything else. I wouldn’t dare to claim that this is unbalanced until I actually experience it in a good testing environment, and that means playing vs all classes with players that are already experienced with all of the new MoP abilities.
You can be sure devs are paying very close attention to both the PvE and PvP side of MoP, we’re still a long time away from the final version, and there’s still enough time to change anything related to tuning.
Also, making fear instant or castable matters little for PvE, while for PvP it makes a huge difference. So you can be sure that on a spell that is clearly directed at PvP, developers will make sure it feels balanced, and they do take a lot of the feedback from the community when deciding this type of changes, so if you guys actually provide good, sensible reasons, if possible backed up by data, as to why do you think an instant fear with 10 sec cd in the environment of MoP, considering all the new variables that MoP's content brings in, every new kind of synergy that will exist between classes, etc… and after that you still think the ability is overpowered, then I’m sure you’ll get their attention and if it turns out they agree with you, I’m sure a new patch will come fixing the issue.
We're all free to speculate about how every new change in the beta affects PvP Balance, but I'd wait a bit more before jumping into conclusions about how some class will be OP in the final version, there's still a long way to go, and if you want to help us out, we really do appreciate it if you could stop by the beta feedback forum
and gives us your constructive input.