Hmm, I kind of like the idea, but performance worries me.

Performance stats show a lot of time in the templating
library even on a single page load.

Things are already slow enough and calling the TAL/chameleon/jinja2
engine multiple times on every single page to build all the inputs
doesn't seem like it would be performant. I literally have pages with 
thousands of inputs (think an editable index page).

Caching might help, but any cache would have to be per user. Cache 
invalidation also becomes an issue.

Thoughts?