The new Air maxes out at 8GB[1]. It's the Retina MBP that maxes out at 16GB.
[1] I have the i7 model, and absolutely love it. It replaced a mid-2009 15" MBP for me. I would've gotten an Air much sooner but absolutely need 8GB RAM. If 16 had been available for it, I would have gotten that instead.
Right, but s/16GB/8GB/g and the point still stands. People often prefer Boot Camp for reasons other than available RAM, however.
As an aside, one point often overlooked when comparing the perceived performance of the new Air to older models is that all the 2012 MacBooks use noticeably faster SSDs than older Apple-installed options — for this reason, my "stock" Ivy Bridge Air (11-inch Mid 2012, 4GB RAM, 128GB SSD, 1.7GHz dual-core i5, integrated graphics) seems faster for many tasks than my "loaded" Sandy Bridge MacBook Pro (17-inch Early 2011, 8GB RAM, 500GB SSD, 2.2GHz quad-core i7, discrete GPU).
[1] I have the i7 model, and absolutely love it. It replaced a mid-2009 15" MBP for me. I would've gotten an Air much sooner but absolutely need 8GB RAM. If 16 had been available for it, I would have gotten that instead.