We would love. With Epicea we have Changes representing not only class and instance addition/removal... Now the question is also how do we initialize such new added instance variable. That's easy if the slot definition has an initialiser.
Now we have probably to recompile the full class hierarchy. I don't see a way if avoiding this unless we move to a self/newspeak model of inst var accessor. But it can be made much faster than recompiling from source. The idea is simply to disassemble every method from bytecode to an assembler level representation (such as Marcus' byte surgeon or my method massage), adjust offsets and regenerate.
This is what VisualWorks does and it is /much/ faster than recompiling from source.
Yes we should do that.
We are brainstorming on a modular way to initialize objects What are the paths to achieve that in a clever way. Yes the monolithic initialize method is an issue if one wants to be able to add inst vars individually. Lazy initialize toon in accessors is one way. That works well for eg inst vars used to implement caches (although now flushing becomes an issue). There's no such thing as a free lunch :-) I know :) Damien was working on a incremental initialization model with marco