However, I disagree that you cannot run windows. I know a good number of people have spoken about running Windows on their Rev A Airs without issue. I think overall what happens though is you max out the ram and you have to start cleaning up your tasks. Should we have to work this way? Nope.
Swapping to the extent necessary to run my Mac and Windows workflows in 2GB is simply unacceptable.
Maybe you can run OS X with just Mail and Calculator open and Windows with just Notepad open and not significantly swap (in either OS) in 2GB. That's not accomplishing work.
I have to manage tasks in 4GB to avoid swapping -- 6 is more comfortable. 2 is unusable -- I'm itching to get rid of my older CD MBP for this reason, and would love to replace it with an Air, but I'm now thinking about a newer MBP instead. (For me, the weight difference between an MBP and an MB is insufficient to compensate for the smaller screen -- the MBA is a different story.)