Sorry, coming in late catching up to Emails.
Regarding what Dries said, it seems we need a form registry
whether mandatory (declaratory/explicit) or deduced (implicit).
We seem to already have one that Heine wrote, Form Store:
http://drupal.org/project/form_store
There is also Form Corral
http://drupal.org/project/formcorral
These may be good starting points ...