I'd like some of the Wizard direct-damage spells to be buffed, as well. Right now the Druid is the best nuker in the game and the Wizard should at least be able to give him a run for his money at times. Sure, spamming Slicken after level 9 is plenty cheesy, but sometimes I really do just want to sling some Fireballs and Corrosive Clouds.
Barring that, as an inveterate Mage player I'm most looking forward to higher tiers of spells: Horrid Wilting, Finger of Death, etc, and especially epic spells (Xth level in the spellbook UI right now). Definitely thinking of Time Stop, Comet, and so on.