Simple admin aid module idea: Centrally set content type revision defaults

As for most of our sites we want to turn revisions on for all content types, a module (or D7 core patch) to do this from somewhere with a single switch (or checkboxes for all content types in one place) would be nice.

Questions:
* Is there already a module that does this, hiding from my searches?
* Should other per-content-type workflow settings also be centralized?
* Where should centralized settings like this live in the administration menu?

^{benjamin, Agaric}