Libya has never been a stringly united country. Historially the coast is divided into Cyrenaica in the east and Tripolitania in the west witha desert region the Fezzan south of Tripolitania. There are also plenty of tribal divisions. Gaddafi may have decided to abandon Cyrenaica, and possible the Fezzan in an attempt to hold just Tripolitania. His son in a speech recently said "Libya is different, if there is disturbance it will split into several states,". The one thing Gaddafi appears to have plenty of is money. With sufficient, cash, mercenaries and local tribal loyalties it is not at this stage inconceivable that Gaddafi could hold onto Tripolitania and abandon the rest of the country.
U.S. defense contractor accused of copying secret military documents (Reuters)
from the article: Barak: Mideast unrest mustn't culminate in revolutionary regimes