Rename asset file upon upload?
Craft has the ability to dynamically add subfolder paths to Assets when you are creating the Asset field in the control panel. 

Tags like {slug} and {author.username} are some of the available options for creating the directories.

I know it has been brought up before and they have acknowledged the possibility. So who knows, maybe we will see it in 2.2? 

For now, if organization is a concern I recommend using subfolders to keep it clean.