They’ve revealed a new class, the Wizard, which is a logical advancement of the original Mage and DII’s Sorceress. I personally don’t care for much of the spellcasters, but Wizards do look like they have interesting skills.
Of particular, Disintegrate sounds fun to use. PEW PEW Divine Busters anyone? There’s also Arcane Orb, Temporal skills and the whole Conjuring skill tree that may make playing a Wizard a lot more hands-on than the Sorceress and Mage. One minor thing I notice is how much the skills sound like they come from DotA in terms of the effects and descriptions.
In any case, I wish for a solid release date for DIII, like every other fan. I’m currently hedging my bets for a 2010 release date.