It seems that the uprising against Gaddafi has reached its final stages. News reports indicate that rebel forces are outside Tripoli and are perhaps coordinating with an uprising inside Tripoli itself. At this point, rebel victory is only a matter of time.
What remains to be seen though is what comes after. The rebel leadership seems to be faction ridden to the point of factions arranging assassinations against other leaders. This raises reason to doubt, but shouldn't be blown out of proportion. These kinds of problems are to be expected in countries without much history of participatory political leadership. This means that the probability that Libya will fracture into competing violent factions is a real factor to be taken into consideration but it doesn't make this result inevitable. Powerful forces pushing against this outcome are also evident, including the current outside military support, political support from the Arab League and especially the United Arab Emirates, and perhaps most significantly the unifying impact of successfully overthrowing Gaddafi.
On the whole, I think Libya is perhaps the best case for how foreign intervention should be done. It is not without risks but as every foreign war has shown the ability of military forces to exert control is largely illusory, Iraq and Afghanistan being the key exhibits here. Military force can at most create a very high level, imprecise form of control that has little impact on the functioning of a social system that has been of greatest interest in modern conflicts. It lacks the ability to create political legitimacy, economic stability, or to address the grievances driving terrorism, these things persist despite boots on the ground. By contrast, the conflict in Libya is serving to generate the political legitimacy that may lead to future economic stability and to addressing the Libyan people's grievances.
This result is by no means assured, we are operating with a great deal of uncertainty about ultimate outcomes, but our actions there have maximized the probability of a good outcome. It's very important to recognize that in these sorts of situations there is no way to have certainty of results or to calculate precise enough outcomes to allow for a formal cost/benefit accounting. We do know enough to have a rough approximation of the relative importance of factors leading to success however. All human action is inherently uncertain, we should not let arguments that point out this essential quality lead us to tying our hands unnecessarily.
Though it helps for my view that I regard the atrocities that have happened after previous failed revolts in the mid-east as the baseline condition. If it wasn't for our support, I believe the situation in Libya would have been far worse than what we're seeing in Syria. Our intervention in Libya may have even had an impact on Syria delaying its use of heavy-handed tactics for fear of intervention, though there's no way to be sure.