looks nice, but still seems to have a fairly grey background. But we can not tell from a video. I was hoping for a whiter background. And it sure looks as it the frame is a bit, well, floppy. Maybe that is to show off the flexibility of the displays themselves.
As for the lines, has to be a prototype thing. Somehow I doubt many people would be happy dropping $350-$500 for a device that has an issue like that.
Overall, looks really nice. How cool would it be to have a 3-ring binder sort of setup for the bezel? That way you could keep it inside a normal folder with any other papers you are carrying...all in one neat notebook sort of setup. It would be easy to just pop it out of there for reading...or leave it in as you choose.