I picked a (beautiful!) black/slate mini up on launch day along with a Smart Cover, but I was concerned about the back (not from any reports of scratches I'd read, just common sense because it's exposed and not protected if you throw it in a bag) so I bought a soft padded case I can slide my mini with Smart Cover into when I take it anywhere.
I use the device daily and there are no scratches on it, or marks or problems at all - it looks brand new still, but I'm not the type of person that mistreats or ignores how he handles/cares for his devices. I'm not the type that demands I or others use gloves when handling my devices either - somewhere in between I suppose.