plone/plone.app.contenttypes — pull request #8 by tisto (2012-11-23 21:28:07+00:00)
Title: Custom content classes

Use custom content classes that implement proper marker interfaces that can be used by browser views and add-on products. At the same time it is still possible to edit the content types ttw because we are using the xml models.

With the new interfaces in place I also moved all skin templates to browser views.

It seems to me that changing the base classes of the content types does not require an upgrade step. I'm using plone.app.contenttypes in a medium size Plone size in production and I successfully tested the upgrade to the custom-base-classes branch.