I'm working on a bilingual site, and needed to have the help value for a content type (the submission guidelines that appear at the top of the node form for that type) be translated, which they don't appear to be by default.

I believe I tracked down the problem, on line 44 of node.module:

    return '<p>'. filter_xss_admin($type->help) .'</p>';

Based on this, the string is never passed through for possible translation. The fix is simple, though:

    return '<p>'. filter_xss_admin(t($type->help)) .'</p>';

Thought this might save someone else some time if there encountered a similar problem.