World leaders today are a boring bunch...technocrats often, or worse, ideologues. Gadhafi cannot be classified as either a technocrat or as an ideologue (that is for sure).
Gadhafi was the first postmodern leader. He altered his look and temper often, no doubt purposely, as part of his ruling style. These changes prevented enemies from grabbing hold of his image, fixing it as evil, mad, brilliant, stupid, or anything else in particular, thereby making it more difficult to target him. That's what will be missed...the lengths he went through to play with power and to dominate it (watch Berlusconi for some of the same moves).
What arises as a serious question today is whether his pomo style was necessary to govern a place like Libya in modern times, whether it was a function of his own personality, or both? This is an important question because it is the question that Libya faces now.