its not only used for death. You can blend ragdoll with normal animations. In the Havok2 demo they have zombies walking around, and when shot by a gun their ragdoll physics made them take hits-- but they keep coming at you. If you only hit their shoulders they half-turn from the torso up, and their speed is slowed, but then they right themselves and keep coming after you.
however, its definately more of a finesse than a vital feature
a screen cap is worth 0x100000 DWORDS