At BlizzCon this year some lucky people got a chance to play Diablo III’s Arena PVP. Competitive gameplay that requires team strategy, but still has your classic Diablo elements where one skilled guy goes 3v1, nice!
There is some crowd control, but each class has an ability--with a long cooldown--that will break any roots, snares, and other effects. Additionally, each class has an ability that helps them move quickly around the map be it teleporting or sprinting. The spells at my team's dispel worked well together and we could easily kill opponents if we caught them unaware in a stun.
That isn't to say that a single player cannot defeat multiple opponents with careful skill use. Faced with a one-versus-three situation—I was the one—I used the Wizard's spells to defeat all three opponents.