In our JIRA implementation editing of issues is only allowed for privileged users who don't need to justify why they're making a change. We have a lot of fields on our edit screen and even with tabs it's a bit cluttered. We'd like to be able to nix the comment field on the edit screen to save a bit of screen real estate and clutter. A drop-down on the Edit for a screen to enable or disable the comment field would be nice... it could even be combined with http://jira.atlassian.com/browse/JRA-4972 to a single drop-down as follows:

Comments:

Disabled (Ability To Leave Comment Does Not Appear On Screen)
Enabled And Not Required (Comment Is Optional)
Enabled And Required (User Must Leave Comment)