Documentation for hook_element_info() is very outdated, talks only about Form API, does not document #theme, #theme_wrappers

The API doc for hook_element_info() is extremely outdated---it only talks about form elements (even though the "elements" provided through this hook are now types for renderable arrays, cf. system_element_info() and http://drupal.org/node/930760 .

It also does not document the vital #theme and #theme_wrapper properties that are used in such more general elements.

I'd be willing to roll a patch in the next couple of days to get the doc for this function updated, unless someone more experienced than me wants to step in.