Both the Find toolbar and the Find & Replace dialog should include a progress count of the form "Highlighting match X of Y total" or something like that.
As it is, simply typing a term into the search text field and doing nothing besides clicking "Find" doesn't show how many times the term was found, which is not good at all.
Thanks for the idea. I think it would make sense.
*** Bug 106383 has been marked as a duplicate of this bug. ***