So I was in the Apple Store today and the demo unit that I was playing with of the new Retina MBP is pretty sweet. I was typing on the keyboard, and I noticed that as I typed, it felt like something on the inside computer was vibrating as if there was some type of haptic feedback. The keys on the computer seemed noticeably lighter than the "standard" MBP sort of like the 11" MBA's keyboard. Did Apple add some kind of physical feedback device? Am I crazy/get a lemon for a demo unit? I tried another unit and it didn't do it as much.