Why on earth would Qaddafi and those loyal to him surrender? They only face death after trials either in Libya or the by the International Criminal Court. Die in battle or die in jail, which is better? Haven't they been pushed into a position where they must fight to the death? This is a terrible thing, and means fire fights street by street, house by house, hand to hand, just more and more death.
I suppose that the rationale for the International Criminal Court's accusing brutal tyrants of war crimes is that in so doing other tyrants will be forewarned and prevented from committing war crimes. But I don't think that tyrants ever think they are going to lose power, and if they think their reigns of terror are in danger, they just up the terror and kill off the opposition to stay in power. That they will ultimately lose power just doesn't come into their brains, as best I can guess.
Qaddafi seems to have lost control of the country, but that is different than ending the fighting. As I wrote earlier, I expect Qaddafi loyalists to fight on for some time, and maybe even be a counter-revolutionary force in the country for years to come.
I think there is no doubt about Qaddafi's decision: as in the movie "Butch Cassidy and the Sundance Kid" - go out with both guns blazing.