Give it a couple iterations and you'll have something that costs $2k many will purchase in lieue of another Macbook. It will be lighter/more compact, with somewhat palatable battery life. There have been reports Apple is also working on a simpler version, so there could be an Air in a few years that starts just north of $1k.
If this platform is successful, that is. I have my doubts everyone will want to strap a device to their head a large chunk of the day, every day, no matter how incredible.