This question has been bothering me. Qaddafi seems firmly in control of the city for now and even if unrest does occur there I doubt there is any way for air support to effectively intervene.
Assuming there isn't a negotiated abdication of Qaddafi there doesn't seem to be any good outcome for the citizens of this city. The rebels have a lot of irregulars, after a few weeks of heavy fighting in what will undoubtedly be a hard fought push to take the city how much trust we can have about how these soldiers will act in liberating Qaddafi's main stronghold? There is also a possibility of street to street fighting which has historically been very rough on civilians. While I think intervention on the whole saves civilian lives in what would have otherwise been years of brutal crackdowns by Qaddafi loyalists in the short term it is not unlikely that many will see the choice as having been to trade a slaughter in Tripoli for a slaughter in Benghazi.
I just hope there is some form of negotiated settlement or stalemate instead of the city having to be taken by the rebel forces.