Matthew came to my office on Monday and broke an important rule: Former PhD students are never allowed to have better laptops than their supervisors!
Yes, Matt brought his MacBook Air with 64G SSD. Here it is on my desk next to my less sexy Dell desktop:
My impression: It's gorgeous! What impressed me is not the weight, indeed my trusty Dell X1 is lighter, but the fact that it feels like a serious laptop. It's not plastic, it doesn't flex and I don't need to sharpen my fingers to use it.
It's beautifully designed. I take the criticism that one USB socket is a limit. I'm not so sure about the non-removable battery issue. I swapped in the heavier battery in my X1 when I got it, and I've never swapped it out. At least for me, the fixed battery wouldn't be a problem.
I'm still not happy that Matt has one and I don't though :-)