Nationalism is the biggest hurdle on the road to globalization. Once there is just one world-wide government, there will be free trade and the corporations of the world will see unprecedented profit. Once all the races have mixed to a yellow/brown skin, all racism will be gone as well. First it will be a lose of culture and community. Then people will be called Fascist, racist, etc, until they stop seeing themselves as belonging to a certain group and accept the one-world government. It will be good for all, especially the corporate elite!
Yes, the era of nationalism is coming to an end. As the world becomes more and more globalized, national origin means less and less. There are Americans living many places abroad. There are people born in Europe who now live in Asia. There are Asians who now live in America. The world is becoming smaller.
Is nationalism coming to an end? Overall, I don't believe so. In the United States, I believe that it is not so strong as it once was ten years ago. I believe that there still are and always be some zealots though. In Europe and Russia and parts of Asia however, there are many countries where nationalism is still alive and well.
Nationalism is still very present in the world, although some countries have it more than others. As an example, we could see during the 2014 winter Olympics some of the extreme pride that people have for their own countries. Some might point to countries like Russia as having a strong sense of nationalism. While it would be nice to believe we're a unified world and that our borders are merely imagined, nationalism definitely still exists in the world today.
The world is getting smaller and we are all getting to know one another better, but I do not see nationalism ending. I see people who realize how ridiculous nationalism is. But, just take Twitter for example; you see national pride on there all the time, and people disrespecting one another's countries.
According to Wikipedia, nationalism is a belief, creed or political ideology that involves an individual identifying with, or becoming attached to, one's nation. While I believe this is coming to an end in America, I believe it is in response to the further corruption of our government. I think it could go the other direction as well, so I would say the era is dying, its just losing steam at the moment.