Thanks, but I think all the enthusiasm on c.l.l is from me. :) Maybe when I provide a Web app example people will get fired up. (I am a dinosaur, thought a desktop GUI would do the trick);
http://common-lisp.net/project/cells-gtk/
As for controlling change, right, my-obj!my-slot will be a backdoor, Arcells (name?) will have to work via readers/writers that invoke the Arcells engine.
Framework? Test spec? What I have so far is merely motivational examples (and I am using the OBJ macro, not redefining it):
http://smuglispweeny.blogspot.com
Look for (+ Arc Cells) Baby Steps, which I am mopping up once the caffeine hits my cortex. When done I'll submit a new thread.