After peaceful, pro-democracy street rallies that inspired admiration around the world, Ukraine's opposition managed to achieve in a few tumultuous weeks that which no one had done since independence in 1991: It shook Ukraine's stagnant, post-Soviet political establishment to its very core.
Stuart Hensel is a Ukraine expert at the Economist Intelligence Unit in London.
"It is really hard to imagine, given what has happened in the last month, it's hard to imagine them [people] going back to the sort of government that was there before. There seems to have been a certain watershed moment that was passed," Hensel said.
But whether that is true remains the million-dollar question for Ukraine.
On 3 December, the Ukrainian Supreme Court -- siding with the conclusion of Western monitors -- declared the second round of the presidential election void on the basis of fraud and announced new polls for 26 December.
By most accounts, Western-leaning Viktor Yushchenko is poised to complete the opposition's amazing comeback with victory against Kremlin-backed Prime Minister Viktor Yanukovych.
But not everyone is sure. Some wonder whether the exhilarating experience of the past few weeks has been merely a blip on the historical radar -- rather than a definitive break with the country's post-Soviet past.
Hensel, for his part, said a full "rollback" is unlikely. But he added that Ukraine might encounter serious problems in the future.
"I think there are still going to be deep political problems in Ukraine, I think. The level of political party development is still not enough to make parliament a really effective body. I think it's going to be very difficult for Yushchenko to push through the administrative reforms that he needs in order to prevent a new powerful parliament and cabinet from abusing power in the same way that the [outgoing President Leonid] Kuchma administration did," Hensel said.
After the court ruling, Ukraine's parliament amended electoral legislation to minimize the risk of fraud. But in a major compromise, it also passed constitutional amendments paving way for a parliamentary republic with reduced presidential powers.
Hensel said the new administration will face resistance to reforms from the bureaucracy, secret services, and Interior Ministry. And he believes that Yushchenko, whom he says is notoriously disorganized and lacks decisiveness, could become a problem himself.
Igor Losev, a professor of history and philosophy at the Kyiv-Mohilev Academy, is even more cautious. He said it is too early to say whether Ukraine has made a profound break with its past. And he added that Russia still has cards to play in Ukraine.
"Much depends on the behavior of the authorities and, without any doubt, on what Moscow decides to do, how they will accept this voting scheduled for 26 December, and then we will see how the events will develop. I cannot say that these rallies for sure mark an ultimate and irreversible break with the past," Losev said.
Losev added that not everyone in Ukraine supports democratization and that a majority in the eastern regions opposes Yushchenko. A victorious Yushchenko, he added, would have to work hard to become the president of the whole country.
However, the professor acknowledged that Ukraine has never seen such massive protests or popular enthusiasm, neither during the 1918-20 Russian Revolution nor following the collapse of the Soviet Union in 1991.
Hensel also made that point. He said, at the very least, the rallies represent a completely new political phenomenon for Ukraine.
There were also protests in 2001, but they fizzled. This time, Hensel said the rallies were much bigger and took place across the country.
"You know, this is something that no one has ever seen [in Ukraine]. When you look at the amount of people that came out into the streets in 2001 -- the last time Kuchma faced some very severe allegations of abuses of power -- it was nothing compared to this. It was maximum 10,000 -20,000 at one time," Hensel said.
Hensel also pointed out that people clearly saw that the Kremlin was behind Yanukovych and were outraged by Russia's attempt to determine Ukraine's fate. The analyst says that this helped to make the experience galvanizing for Ukrainians, giving them a feeling that they belong to a single nation.
And in that sense, the "Orange Revolution" marks the end of post-Soviet Ukraine. That, at least, is the view of Oleksandr Sushko, who directs the Center for Peace, Conversion, and Foreign Policy, a Kyiv-based think tank.
Sushko said that in these heady days, Ukrainians themselves are laying the foundation for a democratic society. And he believes such changes will become irreversible because it is the people themselves, rather than the ruling elites, who are demanding them.
"A rollback? If everything were simply a conflict among the elites; if a 'Yushchenko' had a quarrel with a 'Yanukovych', and then everything calmed down, [then a rollback] would be possible. But it is evident now that we do not have a conflict among the [ruling] elites. Society has clearly indicated that which it will never accept," Sushko said.
From now on, Sushko believes that Ukrainians will longer accept having leaders forced upon them, whether from within or from without: "It has already become impossible to do that -- and that alone makes all the difference."