The rebellion against him is pretty well equipped.
Right, they have jets and stuff too, from defecting air force pilots. The plucky, ragged renegade rebellion has artillery and jets.
He really does not enjoy any of the advantages of your usual tyrant. He fails at evil.
Strategypage has more info on why the Libyan army was so ready to fragment and have mass defections to the rebels. In short Gadhafi feared a coup from the military (similar to how he seized power) and kept the military impoverished and demoralized, even by Third-world tyrant standards.
And here's more info on what makes Lybia's uprising different from Tunisia's or Egypt's.
Well, at least it'll be hard to have a new regime there that's more evil than Gadhafi's (the man already enslaved Libya into a Stalinist-Islamist state, exported terrorism worldwide and had his own nuclear program), conversely it'll be hard to have one that's more incompetent.
Alternatively why does there have to be a new regime? Why not Somalia on the med?