I was worried it might have been caused by a heat problem (like something was melting the plastic from the inside-out) since it had gotten very hot (seemingly hotter than normal) right before I noticed it for the first time.
If it was a really bad cosmetic defect or something that was (or would in the future) cause performance problems, I would certainly want it switched out, but since it is such a minor thing that I never even noticed before, I just don't really care. My wife doesn't care, either, and it's her computer now, anyway.