There is a fundamental difference between a DJ and a Turntablist. The difference is that a good Turntablist has talent, where as a good DJ has skill.
Club DJs that don't produce the music they're mixing aren't worth a pinch of shit. Glorified pretty boys soaking up the glory for other peoples hard work, then letting it go to their heads! The DJ/club culture is so shallow and fake.
Turntablists on the other hand create usable instruments by messing with Vinyl. I've met guys who could actually play melodies by scratching together 2 records that contained a straight pitch. These are the only guys who I can respect as "DJs".
Just my two cents.
EDIT: I should say though, I'm only refering to the Dance/Club scene where DJs are concerned. These guys take way too much credit. DJs that are mixing other forms of music don't usually have half the attitude.