Karl, we do have a project designing a new CMS for OpenACS which is currently in (a slightly extended) user experience design phase.
These are the sort of issues close to my heart on CMS, and match some of our discussions.
I have posted a link to your post for all the CMS project people to read in our CMS forum, and on the CMS project page (https://openacs.org/projects/openacs/packages/cms-future/).
Thanks for your insight!
