I actually think that the internet may disappear one day by being overwhelmed by malicious software/hackers. The only reason you are able to use the internet right now is because no one is trying to stop you and the people who might try to stop you are not quite as good as the people trying to stop them. But with cyber warfare becoming part of almost every country's defense department and with terrorist and anarchist groups also developing hacking capabilities, it is certainly within the realm of possibility that someone could develop a "nuclear bomb" virus that could take down the internet.
But taking the futurism to its logical limits, it may be that advances in computer memory would mean that the internet would become unnecessary as a tool for getting information. Scientist have been experimenting with using DNA sequencing as data storage. Instead of a series of zeros and ones, data is coded into G A T C. The result is that the Library of Congress can be stored on something that is about the size of a few strands of hair. With this kind of data storage capability, you could have a vendor (say Apple) give you a small drive with just about everything you would ever want (books, music, movies, etc.) and would not need to get data from the internet. The internet would then turn into more of a communications device like old telephones. You would use the internet to communicate with your friends without opening yourself up to strangers through the world wide web.
I will be giving a Ted talk on this next month at the Ted talks at the Holiday Inn in Parma, Ohio.