So I'm having the same problem. It's not quite as bad as the OP's, but it's still annoying.
Some of the little chips I noticed months ago and I pretty much ignored them, but recently, maybe a week or two ago, I noticed many more smaller chips around the edge just in front of the trackpad; in most situations it's difficult to see, but when I'm lying in bed using the computer the lighting makes the marks stand out and look like crap. The chips may be getting worse too; I've been noticing more and more of them, but I don't know if these are new or if I just didn't notice them until now.
My computer runs great and still looks more or less new other than this (well, there's this weird finish issue where the anodization flaked off at the back, but that happened a long time ago and I never did anything about it, though I should have).
Anyway, this issue is bugging me, especially if the wear gets worse. The odd thing is, the chips aren't even forming where I usually rest my palms; the places where there
should be wear are more or less pristine

It's possible I dropped something or bumped into it, but I don't remember doing so; I've also noticed that the edge is slightly sharper on the left than the right side, and it's the left side that's been getting the chips, so I'm thinking there might be a connection there...