I agree it should be more limited to a couple of spells rather than all but not for reasons you've stated. It is precisly like ele shamans and hunters, because all their other CC/pvp spells are instant anyway. Non-existant penalty? The speed reduction is really noticeable and not something I would want at all times in pvp or pve, while ele/hunters dont have that at all.
They have to throw on a debuff with the duration of the spell you're casting or something, or a standard duration of 3 seconds or something, triggered and refreshed by every cast-time spell cast, while moving, stacking up to 2 times, and every time your cast doesn't get interupted because you have the talent, you automatically also instantly apply this debuff: TADAAAH. Talent would work as intended for both Destruction and Demonology (3 second duration is able to be modified to average cast-time of spells in that spec or something). For Affliction it'd probably be a bit harder due to duration of casts, but just apply it on every tick of a channel that you're moving and you're golden too, as long as the duration is right.
PS:
You made me chuckle a bit good sir =3 Although I think most devs DO read forums, they just can't be bothered to respond due to the inevitable flocking of not-so-pleasant forumposters. (read: whiny people and dem trolls)
Ex-GM and Raidleader of the MoX Purple Kittens Raidteam on Twisting Nether (formerly Grim Batol), RIP, Winter 2010 - Spring 2013.
Armory. WoWProgress. Might start streaming Soon(tm) http://twitch.tv/szem/
Just so you know, I knew that affliction will be shit in MoP since beta, the same way I knew warriors and hunters will simply destroy the game, make it unplayable, but guess what... what you, I and those "noobs" you're talking about, think, doesn't matter at all... It's not beta tester's fault for the way affliction is atm, it is Blizzard's fault for just being clueless.... You actually implying that everyone who tested beta thought locks are OP and warriors and hunters are just FINE?
I play a Warlock as a main, besides a lot of other classes, but my heart is with Warlocks and I want them to be good, but not OP, that's the difference between you and me, you prolly just want to Chaos Bolt ppl for 200k while moving.... Keep hoping for that, but when the nerf bat comes, don't say I didn't warned you.
Hunters can do everything while moving and have far more mobility and CC
Honestly, we only really need one spell to work at all times. Shadowbolt (if u take affliction, it turns into mg, and incin for destro). As a demo lock, in pvp, i still wouldnt take the talent. as all I do currently, is basically run around fel flaming for my filler, because, as it stands, I never get a chance to free cast. Pve demo, i am a little in the air, as, sometimes, I cast one extra soul fire... if mc procs fall/are done... and that shit takes forever to cast, so i typically jump. With this taent,i wont be able to stop casting, unless i make a little macro off to the side, but every other spec, i would be using this.
But the no penalty is a bug. I doubt it will stay like that.
Chaos bolt while moving without a casting penalty will actually help us get them off much more easily.