Reading through comments on digg, slashdot, engadget and other places I think there is some confusion. What makes this particular prototype different is that it’s functional. That is, it’s got a working motherboard, a display, keyboard that’s hooked up and you can plug in USB devices. Earlier prototypes weren’t functional. That’s why this one is different.
Also, I spent some time answering questions in my posts last night. If you want some more details, they are worth the read.