One thing that i found annoying is that the TF2 post mentions adding in crafting, so you can combine duplicate items to get something new. If only they said this from the start i wouldnt have been deleting my duplicate items, I would have saved them for when crafting was implemented.
By the time a system like this is implemented you would have loads of duplicates already. But even if that's the case you know they would just reset duplicates anyway.