Hmm, probaby Paladin, Barbarian, Monk, and Sorcerer. These classes I rarely got to play back in my DnD days. I love wizard, but sorcerer always appealed to me. I am curious how they will roll with Bard though and understand why it is something they are taking their time on since it is the class that is literally the jack of all trades.
As far as races I'd like to see. Half-orc (although full Orc would be a nice touch, but half-orc will do), I know Gnome is coming so not too worried about not seeing them, but one of my favorites. Sorry halfling lovers, but gnomes do it better.
Also would like to see the Planetouched (Aasimar, Genasi) and Githzerai added. Would be interesting to see how Laezal interacts with a Githzerai Monk since they have a shared foe, but fight in totally different manners and view points. Not that you asked for that opinion on that, but just something I'd like to see.