Is there any way to customize the tooltips that appear when you hover over the items in the various selection combo lists (e.g. Issue Type, Priority, Resolution, etc). Currently, when a user is creating or editing a ticket and is choosing a priority, for example, the tootip only displays the same name as item, which is not very helpful.

It would much move valuable and meaninful, if it could give the actual item description without the need to navigate to the "?" icon. (In fact, the inline editing functionality doesn't even have a "?" icon; see screenshot.) This would go a long way to educating new users as to the distinction between such choices as "Improvement" and "New Feature".
Based on a comment in the Description of this ticket, it sounds like this functionality was previously available -- is that true?
UPDATE: Looks like I'm not the only one wishing for this functionality.
UPDATE #2: There is a ticket for addressing a closely related issue, now In Progress.