I was actually mistaken. The resolution calls for any necessary measures short of military occupation to protect civilians. It seems to be unnecessary anyways.
Gaddafi is a madman. You never know what he will do when he overwhelms the opposition. On the other hand, nobody knows what the opposition will do if they have an overwhelming victory on their own neither. I saw some gruesome videos featuring the Islamic-style execution of pro-Gaddafi millitary personnel by some opposition groups too. This is a tricky business to handle for the international community.
A ceasefire based on a delicate balance of power between the two sides might be the best solution for the time being.