I think a better term might be "complete", rather than "dying".
When it comes to hardware or software, PCs are pretty much in their final form. Barring processor changes, there isn't really much that can be done to revolutionise the way you do things on them and even then, performance benefits are extremely incremental. They aren't exciting anymore, you will likely still be doing the same work on a PC 10 years from now, and the platform just isn't new and exciting anymore unlike iPads and iOS.
Simply put, I see smartphones and tablets as having the potential to rethink and revolutionise the way work is done in a way that current PCs never could, and the way forward for them is clearly for the iPad to not become like the PCs of today. Else, what exactly is the point, really?