I'm not a Mac fanboy, but the Macbook Air is amazing. Because of a few projects I'm working on, I needed a new Mac and wanted something as light as possible, because I'll often have to lug it along with my daily warrior, a loaded and SSD-ed Thinkpad T400s.
First, the Air is an amazing engineering feat. You've seen the pictures, but until you hold it, it's hard to really imagine how thin this laptop is. I don't have any rigorous performance numbers, but those upset by the use of a Core2 chip instead of one of the newer i5/i7 chips can relax--for virtually anything you'll use this laptop for (barring extreme 3D games, I presume, though I haven't checked out the performance and don't intend to use it for that), it's plenty fast. Lightroom rendered images very quickly, applications open instantly, reboot is blazing, it's very responsive in every situation I've encountered.
It's not perfect, of course. Where (Apple) are the home and end keys? How about pgup and pgdn? I know--Fn-arrow. And del? Yeah, Fn-delete. I want keys. I'm not thrilled with gigabit over USB. I would love a builtin VGA port for presentations so I don't have to lug a dongle, but where would it go? There's not a single spot where the laptop is as thick as a VGA plug. I would have liked 8GB of RAM (I make heavy use of virtualization). But overall, this is one sweet laptop and highly recommended if you need a lightweight Mac solution.
