Key muscles involved in the DL are:
Spinal Errectors (lower back)
Hamstrings
Glutes
Traps (all four sectons, not just around the clavicles)
Forearms
Quads
(and probably in that order)
HEAVY deadlifts will also significantly involve your:
Biceps
Rear Delts
Lats
Calves
Abs
That really just leaves your chest, tris, and front delts completely untouched.
Thus I often like to get a "full body workout" by alternating sets of weighted dips with deads!