This is one of those idea-posts. There is no implementation and no code. But if someone wants to take the idea and do something with it, go ahead.
The gist of it is this: what if you could implement the actions for AspectJ in Ruby? You could define an on-load pointcut that matches everything and dispatches to Ruby. From there on you could do basically anything from the Ruby side - including dynamically changing the stuff happening. Of course, there would be a performance cost, but it could be incredibly useful for debugging, when you don't really want to restart your application and recompile every time you want to change the implementation of the aspect code.