According to Diablo 3 lead designer Jya Wilson, Blizzard liked the idea of the Monk because he's fast, "but is also fragile. That's a really interesting contradiction that we thought would make for good gameplay." The team referenced Diablo II's Assassin and World of Warcraft's Rogue in redesigning the class. The Monk will be defined by its combo moves, holy magic, speed, and complementary skills. Wilson said that the Monk will be a bit harder to pick up for players, but that they didn't mind adding a class that required more skill in the early game.
Designer Wyatt Cheng then introduced several of the Monk's lightning-quick skills.
Way of the Hundred Fists: "The player is actually hitting the same mouse button three times in a row.. but every time you use the skill, a different move [occurs]." Cheng compared the combo move to something you'd find in a console brawler.
Crippling Wave: "Slows your enemies on the first hit, applies a damage debuff on the second hit, and then refreshes the duration of both on the third hit, as well as doing a little extra damage."
Exploding Palm: The attack does damage and applies a moderate bleed. When the target dies, it explodes, dealing damage to surrounding enemies that is proportional to the amount that it bled.
A beginner can spam one of these skills, but veterans can combine the moves. For example, a player might open with the Hundred Fists, follow with Crippling Wave, and end with the Exploding Palm.
Blizzard then detailed the Seven Sided Strike: "It's a lot like chain lightning from Diablo 2, with one difference: you are the lightning." On screen, the monk strikes several enemies, bouncing from one to the other with yellow Street Fighter-esque effects.
So, this guy takes up the spot of an assassin I assume? With being fast and fragile.