I wrote a paper on bootstrapping a reflective system that might be of interest to some people on this list:
http://www.lsi.usp.br/~jecel/jabs7.html
An updated version of that paper is a chapter in this book:
"Advances in Object-Oriented Metalevel Architectures and Reflection" Edited by Chris Zimmermann CRC Press, 1996, ISBN 0-8493-2663-X
This was intended to complement "The Art of MOP" so it might also interested somebody here (though it is a bit expensive).
About Aspect Oriented Programming: a key feature of a good MOP is the "separation of concerns". That is, you shouldn't have to mix base-level code and meta-level code in a single source. It would be nice to be able to entirely write the base-level program (and even test) and then turn your attention to meta-stuff and write it separately (for better understandability and reusability). An example where this doesn't happen is when your meta-language is in the form of annotations (or "pragmas"). If you segregate the meta-level into special objects, you get much closer to this goal.
Now it happens that this separation of the sistem into two "aspects" (the base-level and the meta-level) is simply too simplistic. We could go a step further and separate the data distribution aspect of the application from the communication protocols aspect. You might find it useful to also break up the base-level into separate parts (like VRML separates the 3D structure aspect from the interaction aspect by coding them in totally different languages). So the main idea is to write several simple programs in specialized languages. But this is not to be confused with some kind of modular programming! The compiler must "weave together" the sources from all different aspects into a single object code. Please see the AOP pages for an example. This is closely related to implementing reflection by doing a partial evaluation of the meta-level and sticking it into the base-level's object code.
The bottom line is that I find AOP very exciting, but not really needed if you have a *very* good MOP.
-- Jecel