I think, the wonderful Info-Column of "Last 20 issues" widget of the dashboard is heavily underused.
Some time ago I modified include/blocks.inc.php to show a little question mark not only for JMX-Triggers, but also for Web Scenarios. The contents of "Last error message of scenario" gets displayed on mouse over or click.
I used already working function for selecting related items for trigger by setting 'selectItems' => true and calculated the proper id for the error message from the item used in the trigger expression.
It seems to make a lot of users happy-happy-happy. Maybe it could be included in some future release?