My wife's phone has some small scratches. Almost seems like there is some thin layer on top of the glass that gets scratched
I would assume there is an oleophobic coating on the glass, as there is with most modern touch screen devices these days. One important thing to note: this is going to scratch much more easily than the glass itself.
All that said, my phone has been dropped, a short 6 hours after buying, by my dear wife (love you honey!) right on the wood floor near the entry (probably the dirtiest grittiest part of the house...) and while there is a slight scuff on the top right corner of the casing, the screen looks good as new, even though the phone did a bit of a spin on the screen side. Everyone's mileage is going to vary, but if you are in a dusty, gritty environment, you are likely to get scratches. I tried a zagg on day one, but just couldn't deal with it. It was too rubbery, picked up fingerprints worse than the glass, and distorted the screen much more than any scratches the screen might accumulate ever would.