I'm still constantly amazed by how absolutely unstoppable my frost mage is when it comes to leveling. Especially with the water elemental glyphed to make it permanent. Not only is the frost spec very mana efficient, but the slowing and freezing effects of the frostbolts make it so that about 70% of the time, the mobs are dead before they get anywhere near me, and for the ones that do get anywhere near me, my Ice Barrier makes me pretty much impregnable and I'll have two instant casts available to take them the rest of the way down in Fire Blast and Cone of Cold. More than enough to take them out.
I did pick up Arcane Barrage at level 64 and tried it out on a few mobs to see how it would do. Obviously I'm not spec'd into Arcane, so it's not at its full potential, but it seemed to be a lot less mana efficient, and wasn't doing noticeably more damage than my Frostbolt crits.
So now I'm putting the mage back on the shelf for a little while and will be going back to my enhancement shaman. I've still been thinking about switching from enhancement to elemental now that I'm higher level. I'm just a bit more of a caster at heart, but we'll see. It's still fun unleashing the ghost wolves on everyone and watching them create mass chaos.
So, the Frost Mage is currently sitting at 64, and the shammy got to 63 last night. Still targeting late August to have these last four toons to 80!