Ah well.. it's something constantly asked, but never fulfilled. As far as i've read in previews, it,s -again - the same standard classes with some specialisations - some new some old.
Geez... i so wished they would start putting effort into the class-system and add something fresh ans new. Hell, i could event hink of three and more right from the start, i would like to play.
A mage-class with no offense-spells that has to rely on summoning minions, which he can buff er even use as walking bombs.
A warrior-mage-class that can only enchant his own equipment(but not wear armors) and give himself special treats and buffs... like blur hiimself to make him harder to hit or making a cutting weapon do blunt damage to adapt to enemy resistances.
A distance-tank-class like a warrior using shields and throwing spears.
A cleric that can either fight or use auras to create field-buffs (like health or stamina-regeneration or damage resistance) which makes him immovable.
There are so many possibilities with potential that would add to the tactical combat. High variety in classes is one of the things which makes AD&D so great... not just some specialisations with a handful of skills but no heart inside.
...but like i said, it's very unlikely.