Yes, I know that this is possible. But are you really proposing to start a project like this? Or do you mean Five is going or should go in this direction?
It (or Zope 2 development in general, which is becoming indistinguishable from Five) is going in this direction.
Just an outsider's naive comment on this: These days all of my plone-based z2 products use z3 interfaces, adapters and views (via Five). I look forward to using more five/z3 functionality everyday (such as events, etc). I'm sure this is still a long way from using pure z3, but with every new version of z2/z3/Five I hope to get closer and closer. - Rocky -- Rocky Burt ServerZen Software -- http://www.serverzen.com ServerZen Hosting -- http://www.serverzenhosting.net News About The Server -- http://www.serverzen.net