I have been arcane since the patch, mostly because I spend too much money on alts and can't afford to respec. But i love Arcane barrage, I 3 shot a warr in AV with just arcane barrace, fire blast, arcane barrage. It really beefs up the arcane spec to get out of sticky situations. So much of the frost tree is gear towards pvp, I think you can't lose with either fire or arcane for pve.

I'd drop one of those ice lances out of your cast sequence, it is only a 3 second cooldown, so arcane barrage, fireblast, icelance