your priority is hit > sp > haste > crit
as arcane also sock for the socketbonus if the bonus is 7sp or higher
your spec seems ok but seeing the fact you use 2part t9 i would go for
3/3 student of the mind and 1/2 magic atunement
also aim for 11% hit shown on your charscreen if you dont wanna count on a shadowpriest or boomkin in your raid.
you can check my armory if you want to see what a "standard" icc geared mage should look like stat wise. armory "Cincia" on EU-Mug'Thol since i cant post links