WotLK around the corner, my choice of leveling; Quad-boxing.

[Jaws5]

I have found that Arc/fire mages are better than frost ones for Heroic 5 mans. You need to burn down mobs very fast. Arc/fire does that very well.

3 locks also good
3 shammys also good
3 hunters are even good

[Leerill]

Ok, I have now tried both Arcane Fire and Arcane frost (solo). Arcane fire's burst is absolutly crazy, not to mention it's DPS is always very high I was only using fire spells. With Arcane Frost I was surprised, I felt like a hybrid mage tbh, using arcane and frost spells, spamming frost bolts until I get a clearcast and mauling my Arcane missles button then :P

Meh looks like I'll just have to wait and see.

Thanks for the help guys =]