Check this out: If I run my fingertips lightly over the lid while it is closed and the charger is plugged in, my fingertips have a weird vibrating sensation. If the charger is unplugged and I do the same thing, the texture feels normal like any other macbook. If I have the lid open and have the charger attached, I can run my fingertips over the back and feel the same vibrating sensation. If I then ground my other palm on the case, the vibrating sensation goes away. There's clearly something electrically weird happening with the case. I'm wondering if this is a defect or if everyone else with a retina has the same issue?