I like this as well. I sometimes have object in my event sheet that no longer do anything, but I'm afraid to delete them because it might break something.
A general search would be helpful, and when an object is deleted, if that search was done within the confirmation message, it would work well (like what Ashley has suggested)
"This object is is used:
Event Sheet XYZ, Row 103
Event Sheet XYZ, Row 104
Event Sheet XYZ, Row 298
Event Sheet ABC, Row 10
Are you sure you want to delete?"