A nice quote from an AppleInsider review of the MacBook Air with the solid-state drive:
Most critics of the MacBook Air have largely focused on what it doesn't have in comparison to the full size MacBook and high end MacBook Pro. This sounds a lot like complaining that a convertible lacks seats for six adults and the cargo room of a minivan. What's more interesting about the Air is how well it serves the purpose it was intended to achieve: a light, thin, and highly mobile laptop.That's a good way of explaining how computers aren't a one-size-fits-all thing anymore. Apple is cleverly trying to get its dedicated users to buy more than one current machine.
I'm not that interested in the Air right now, though. The 'tiny slightly underpowered portable machine' category is already filled for me right now by my trusty old IBM ThinkPad X30. It's a dual boot XP and Ubuntu Linux machine. I mostly use it when I'm working on a distinct piece of code - I set the terminal window to full-screen and run EMACS in it and can really get down to things without any distractions. It's also geeked out (hey it's a Linux machine!) with a Serenity wallpaper on it and a Matrix rain-of-green-letters screensaver.
I also have a vintage 12" PowerBook, which I don't use for programming much anymore. It's particularly slow now (886 Megahertz) and "The Nightmare Before Christmas" is permanently stuck in the DVD drive - so I keep it as a standby machine for surfing the web and occasional blogging (like now).
By the way, the big takeaway from the article is that writing to the flash drive is actually slower, but reading from it is way faster - 18 times faster for random-access reads.