Well I just think it would be odd not to include at least one ranged type class. My guess it they may introduce guns in a character class such as a engineer or something of that nature. Not like machine guns or anything but like old musket type gun or something weird like that.
I don't agree with this statement from the original post. The other classes can not decimating their opponents from all ranges. The Barbarian and Monk don't have ranged attacks. For them to attack, they have to be right up on the opponent. It seems that you might be taking attacks like the barbarians leap attack, or the monks teleport attack that get's them to the enemy as from all ranges, but that's not the case. They are just attacks that get the barbarian or monk to the location of their opponents. That is not considered ranged. They are both close-range classes.
I consider the WD mid-ranged due to limitations on skills. Insect swarm is slow and requires close range. Firebomb is slowwwww, but it' long range. It's going to be difficult to hit a moving target long range though.
The only long range class that can blast their enemies from a distance and stay at a distance is the Sorceress, even though many of her skills are more close range than I'm used too with the D2 Sorc. She is no doubt considered by Blizzard to be ranged though. Normally, they have some sort of long range, melee type character, which in my mind will no doubt be someone using a gun or bow or amazon type character.
Either way, we'll find out when we find out.
We dont know all the monks skills... maybe he has FOH :).
Last class is going to be a ranged class because they do not have a truely ranged class like the Amazon introduced yet and it would not make sense for them to take that type of class completely out of the game.
My guess is a engineer or gunner and the last class will use some type of gun/cannon thats old school. That would be my guess.