Since the fix in coefficient for fireball, and the bonus you get from empowered fireball the only real spec for raiding(and since 2.3) is 2/48/11
Icy Veins is a must, and unless your raiding guild is VERY bad, they should always put mages with shadow priests, this negating the need for clearcasting.
My suggestion is this build :
Talent Calculator - World of Warcraft
ofcourse, this spec isnt purely PvE, because no one does JUST pve any more.
pure fire is always the best way to deal DPS if you have good crit and hit
currently i sit on 1000 fire dmg with 34% crit 16% hit, and im able to put out roughly 1.1k DPS
frost with the same level of gear is at about 900, and arcane fire you really are laughed at if your raiding anything beyond karazhan.
hope that helps you.
Sadly, you will find if you want to be sereous about PvP as a mage, you need to spec frost, something like 0/5/56 is the normal spec good mages take (
Talent Calculator - World of Warcraft)
Dydus