I'm not sure that the per-bean overhead of spring is significant compared to the overall background noise of using Spring at all, or at least of using Spring with XML. I was thinking about how hard it would be to go to zero-xml -- have our own factory that didn't read xml, not even from fastinfoset, for the core configuration.
We could use cascading contexts: we could have a context that 'springs' into life with the core, always-the-same, beans, and then a normal XML context that cascades to it for the optional items. I could be wrong here: it could be that moving more initialization from beans declared in Spring to ordinary objects created by the default bus would in fact be a win.
