Show signature in Sent Items
It would ease concern among users that the signature is definitely being applied to outgoing emails if they could view the Sent Item with the signature as you can with other signature management software like Exclaimer. It would also help to identify an issue with signatures/incorrect format or styling as users will more likely notice a problem. At present, they are completely blind.
Users are even requesting that we move back to local signatures which have a whole host of issues.