Hi, I don't know if this has ever been proposed before. I will shoot my idea.
Add a safety option regarding photo deletion in lightroom. It has happened to everybody. You have been working on your pics all day and all night to be ready before the deadline. Your tired and you can barely see in front of you anymore. Within your confusion you decide to erase some pictures to clear things up, and BOOM. You made a mistake, and your work is gone. there is a chance you might recover them, but there is a bigger chance that you won't.
So the idea is simple. Add an extra step. Not a warning dialogue, but an extra step. Like a trash/recycle bin inside lightroom where you can review what you are about to send to the digital photography graveyard.