Improved Mindblast

Let's start with a brief history lesson.
Mindblast used to be instant. It was once the priest version of fireblast, or a shock type spell, and was given a cooldown accordingly. As it so happened, you used to be able to channel mindflay while running (imagine that), so a priest would never have to stop to cast. And that was overpowered.

So mindblast was given a 1.5 second cast time, but the cooldown was never fixed (mindflay was also changed to what it is today). Mindblast then became the priest version of lightning bolt, and priests never had an instant nuke again until SW:Death. And that's the end of that story.

Now, here's the issue: basic damage spells of this type are not supposed to have cooldowns. Lightning bolt is spammable, and so is scorch, searing pain, fireball, and shadowbolt. Mindblast having a cooldown is really a result of its legacy as an instant spell.

Furthermore, mindblast is the worst of its category in terms of scaling. Because 1.5 second spells share the coefficients with instant cast spells, so mindblast scales like fireblast and shock spells (42.9% according to Nightshroud's Lux et Umbra). It is also the only non-instant direct damage spell to have a cooldown, so shadow priests are really getting the short end of the stick here.

But wait, what about the 2.0 second lightning bolts or 1.5 second chain lightning? The simple answer is that these spells can be talented to cast like mindblast but retain their base spell coefficients as 3.0 second and 2.5 second spells, respectively. Even immolate, shadowbolt, fireball, and frostbolt can have their cast times reduced similarly (none of those spells have cooldowns).

The suggestions:
1. Improved mindblast makes mindblast instant. The damage coefficients stay the same anyway. Unlike
chain lightning or lightning bolt, we do not get any scaling benefits from it.
2. Improved mindblast reduces mindblast cooldown significantly. Now it's like every other nuke in the game, except it scales less with gear.
3. Improved mindblast reduces cooldown of both Mindblast and SW:D by small amount. Let's be honest: 12 seconds is too much in pvp.

A quick aside on the SW:Death vs. Shadowburn debate:
The notion that the two are comparable is ridiculous. Locks have so many spells that shadowburn is just icing on the cake. If locks want to try it out for themselves, then remove shadowbolt, incinerate, soulfire and immolate from your spellbooks. You should be left with only searing pain except it has an 8 second cooldown, and you must restrict yourself to two dots. Then, you have your beloved shadowburn, except it does blowback damage and a 12 second cooldown. So the rest of the time you just have to channel drain life except you don't have fel concentration and it only heals for 25%, assuming you have 3 points in vampiric embrace. Oh, and no fear except improved howl of terror, and absolutely no deathcoil. And... no pets and replace your lifetap button with a super mana potion, at 5g a pop.
Welcome to the priesthood. Enjoy.