Went to Best Buy with the wife and played with an 11" Air today. I have to say it's a fantastic little machine. The extra 1" over the netbook standard 10" really makes a difference and in comparison to the 13" it feels significantly lighter because of the smaller surface area. I have to say that we're really liking the 11" MBA... BUT... We won't be getting one.
If this came out last year then Id be all over an 11" Mac. But in a world with the iPad then it makes more sense (to us) to have a "Giant iPod Touch" than a "Crippled Mac". It's a shame because I really want one but 999$ for a 64GB 1.4ghz C2D just isn't worth it for us.
If you already have a desktop or laptop, then the iPad would be the perfect companion. Unless you are involved with creatives such as design, photography etc, than a laptop would be better. But the MBA wouldn't be the best option for running Aperture, Final Cut, Adobe Suite, etc.