I think jQuery is on its way out, part of that makes me sad and part of that makes me happy. I have many memories of using jQuery in projects over the years, some went well, some did not. But I don’t think I would use jQuery in anything in the future that was not totally trivial. To understand that we have to look back at where the Web was in 2006,
In 2006 the state of web development was very different, first of all browsers were a lot more primitive. Google Chrome was not yet around so we had Internet Explorer v6, Firefox, Safari and Opera. Each of them had some major bugs in the DOM API, so the first major thing that jQuery did was provide a layer that allowed you to write to a common API and not worry (much) about the differences between browsers. This was a huge saver of time, money and tears!
Secondly the state of the DOM apis at that point was also not as nice as it is now. Many things you might want to do (Select nodes by ID, CSS classes etc) were just not easy to do. jQuery made that easy to do. You could select a group of nodes and then perform some operations on them. It was elegant, it was easy to write (Though harder to maintain and test). It also encouraged some things, like storing all information in the DOM that later seemed like Anti-patterns, but like all patterns and anti-patterns that is only obvious after the fact.
Third in 2006 we were just starting to figure out Ajax. The original Paper on Ajax by Jesse James Garret had just come out in February of 2005. Before that web pages depended on page reload to communicate with the server! And in those days you had to have 2 different versions of your request code one for MS Internet Explorer and one for Firefox. By using jQuery you made that much easier.
To be blunt I think jQuery was and is a great library. I however think that it was created to fix a set of problems which are no longer the main problems web developers face.
At this point the question should not be is jQuery dead (no) as is jQuery ready to enter an honorable retirement? To which I would say yes.
So thank you for the memories jQuery, you moved the state of the art forward!
To be fair I will continue to use jQuery for some limited places in test code and the like.