My worker dragging it on the dusty monitor happened yesterday so it wasn't in my reply on Reddit.
I wiped the display phone vigorously twice, the second time was after the back was clean. I did notice new marks. When I say wipe it on my jeans I don't mean just gliding it over, I mean really rubbing it in your jeans for a good 10 seconds or more.
I don't expect the Jet Black finish would scratch as bad as an iPod Classic because they're different materials with different finishes, just providing my personal experience as a user who runs my phones naked. Realistically there will always be micro particles on clothing, and i upgrade yearly so it doesn't bother me.
Okay, if in the end, the scratches on the display unit are literally only visible if you look in at it in a certain angle, then that's expected. People are under the false impression that the JB is easier to scratch and that's not the case. The glossy black finish simply shows them more easily even if the same scratches are present on glossy white finish.
I fully expect my JB to look the same (or better) than my black iPhone 3GS after one year, as I'm treating them exactly the same (wiping on my jeans, etc.).