This deck worked well.

I beat Maexxna on heroic the first try after building this mage deck for her. It's got plenty of board clear and cheap come into play abilities. Wild Pyromancer, Elven Archer and Voodoo Doctor were great. I think an owl would have been a good addition for the repeatable silence, and maybe Earthen Ring Farseer would be good.

2 Mirror Image

2 Abusive Sergeant

2 Argent Squire

2 Elven Archer

2 Mana Wyrm

2 Voodoo Doctor

2 Arcane Explosion

2 Frostbolt

2 Doomsayer

2 Knife Juggler

2 Murloc Tidehunter

2 Wild Pyromancer

2 Polymorph

2 Blizzard

2 Flamestrike