So we've got what, Barbarian, Witch-Doctor, Wizard & now Monk. So all that is left is a ranger-type char, ie: a meld of the Amazon and the Druid from, D2.
There's only gonna be five classes to begin with, right? So that is pretty much that? With all the health globes falling all over the place you won't need a dedicated cleric class, with Barb and Monk we won't be getting another melee+healing class like the Paladin (and besides, it could be argued that the Monk is just another take on the Paladin), and it feels like any group would be pretty range-deficient with only the Wizard as ranged class. Maybe they will surprise us, but seeing as a Ranger/Hunter class fills in basically everything that is missing (ranged attacks, spears/javs, crowd control via nets/some sort of nature magic, animal companion summoning) other than straight up heals (which they could throw in I guess, as nature heals?) and solves the problem of the Amazon being sex-specific I thoroughly doubt it.