If you want to play 3rd person with a Gears-of-War-like camera, just add this to your Documents\My Games\Skyrim\Skyrim.ini?

[Camera]
fOverShoulderCombatAddY=0.0000
fOverShoulderCombatPosZ=15.0000
fOverShoulderCombatPosX=55.0000
fOverShoulderPosZ=15.0000
fOverShoulderPosX=55.2000

I'm having a nice time with this configuration.

NOTE 1: For some reason, after loading my game I had to unequip my weapons to update the camera.
NOTE 2: Haven't tested with horses.