I take you point that dynamic modification is not the sole purpose for AOP, but it's a perspective that I have used to explain the benefits of AOP to many people. I have found that people can understand it quite easily which helps to reduce their learning curve.
When I first tried AspectJ, the fact that point-cuts etc. are defined in .java files meant that eclipse would show the new keywords as errors in the Java perspective. What I really liked about Aspectwerkz is that the advice is java compatible, and in fact the secondary weaving step is not needed when running in on-line mode.
I think for a developer looking to integrate AOP into there development process Aspectwerkz allows for a gentle introduction. Whether they continue to use it having mastered the concepts is entirely up to them. Jumping head-long into AOP with AspectJ does have a steeper learning curve which could be enough to put some people off the concept.
AOP has a bright future, though, and I think we'll see its popularity grow very quickly. Hopefully people can use this (deliberately simple) article to get going, or at least commit to future researching the topic.