I'm half-Middle Eastern; my father is Iranian. I've been watching the uprisings in the Middle East fairly closely, and I'm optimistic about the rebel's prospects at ousting Gadhafi. And this victory will rest squarely with the courageous leaders of this uprising, not with any particular Western leader.
Most Westerners know very little about the Middle East, let alone anything about the forces that have made the Arab Spring possible.
First things first - the Arab Spring has come about despite of the West, not because of it. Obama's Cairo speech was initially met with some interest, and a hope that Obama would be different. Within a few months, he was widely ignored as incompetent or worse. He still supported regimes that were traditional American allies, but are widely hated in the Middle East. Drones are still killing innocents. He was not going to be some force of change that Middle Easterners hoped he would be. NATO's help with the Libyan rebels was ineffective for a time - despite the NATO bombings, for a time it seemed as if Gadhafi would prevail against the rebels.
The Arab Spring has been possible because of the people, not because of any forces in the West. Over two-thirds of the population is under 30. Unemployment is ridiculously high, including among segments of the population where employment has been OK (like college grads). There are simply no economic opportunities for the youth within the current system. And there were no opportunities to really have a political voice, either.
On top of this are some seriously sadistic and brutal regimes that are aging. Gadhafi has been grooming his sons to take over for some time. I'm guessing that some in his regime got fed up with this, and quietly began defecting. (By the way - that is what happened in Egypt - and the Egyptian military is set to take over, not the street councils that organized the protests.) These defections made the revolts possible. The same thing happened in Egypt; Mubarak was widely seen as grooming his son to take over, and he has been in ill health for a while. In Egypt, I am positive that the generals in the military had been waiting for some moment to institute a coup to ensure that Mubarak's son would not become the Egyptian leader.
All it would really take to topple these regimes would be some spark, and that is what happened with Tunisia. As an Iranian, I'd like to think that the Green Movement had something to do with it, but I know better - Iran has a completely different system of government. Plus, Arabs don't like us very much.
The reason why this did not happen sooner is largely about demographics: over 2/3 of the population of most Middle Eastern nations is under 30. The youth in many of these nations felt like they had no future, and they have never known any other leaders. Past generations fought against colonial influences, and ended up with national dictators. Preferable to colonialism for a time, but not anymore.
PS: Most Western nations have supported dictators in the Middle East to a greater or lesser degree. Gadhafi has never been one of the favored ones - the recent "alliance" between Libya and the rest was really an uneasy truce so that Gadhafi would not get a nuclear weapon. Gadhafi admitted to trying to get one. It's not surprising that the West dropped him like a hot potato as soon as the revolts started, and equally unsurprising that the West declared the rebels to be the real government of Libya.
PPS: Obama did not, in any way, shape or form, enable Middle Easterners to rise up against their leaders. That is highly insulting to Middle Easterners who risked their lives and have died for this. And frankly, Obama's Egypt stance was a disaster - he supported elements within the military, not the leaders in the streets. The Egyptian revolt started when Obama still supported Mubarak, and Obama took a long time to distance himself from Mubarak.