Unless Bitcoins are accepted by a significant portion of the merchants (may be 20-30%), we won't be able to call it as a mainstream currency. Adoption by a few big names will definitely give a boost to the exchange rates, but that alone will not make the currency mainstream. A lot of challenges are ahead... especially the government regulations. 

Mainstream is a pretty relative notion. In my opinion, I already consider it mainstream, as I use it everyday since.. a long time and a lot of my friends use Bitcoin as well.
So among my entourage is quite popular and mainstream, even more than PayPal .

I think we can call it mainstream when we see it on every single website. Still a path ahead, maybe in 4-8 years

I know many bitcoiners have an anarchist/libertarian perspective of the world, therefore, they look at the government as a bad thing.

But the creation of a government controlled by the people is one of the most important political inventions of humankind. We managed to tamed the most powerful institution on Earth: the Leviathan of Hobbes. If the government would disappear tomorrow, I think we know what would happen: most streets would be controlled by violent groups. We would living on a brutal feudalistic system in no time.

The state has important functions on stimulating the economy on depressions and social functions supporting the poor that seem to be unviable or hard to execute on a monetary system where money is finite and it's in the hands of a group of pioneers (our hands).

Take the creation of the money from the hands of a democratic government (I know in many countries that power isn't in the hands of democrats), make it finite, and in the hands of a group of pioneers, and rest assure that justice won't be served.

But my text isn't about justice. There is little that we can do. I certainly won't try to convince governments to destroy bitcoin. They will have to do their home work. It's only about taking conscience of what might happen.

Be careful with what you want, because it might come true.

I think this is a reasonable assessment. I agree that the volatility isn't going anywhere anytime soon. I think you're right that it will have to get to the point where the emotions of the crowd are not the driving factor on upswings or sell offs.

... Because I doubt bitcoin will bring much prosperity, since it will establish a deflationary monetary system. ...

Freedom is a completely abstract notion. You are technically taking power away from the government by promoting Bitcoin, however you are in turn giving power to a select handful of people who have large holdings of coins. It doesn't give the power to collective society (if anything democratically elected governments do so on the behalf of the people) but instead some individuals.