I know, but my thinking, always buy the most RAM you can afford, and For $100, go for it, you'll thank me later
Have to agree, and the biggest thing many forget is that while 2GB of RAM seems sufficient now, LION is just around the corner. The easiest thing to improve the usable life of the MBA is to upgrade the RAM. I would say it will take it from two years and definitely be stuck at Lion with only 2GB RAM. With 4GB RAM, it will be marching years into the future with probably five useful years or more. With Lion so close to being released, it is almost ridiculous that Apple hasn't moved these to 4GB RAM standard... and I do expect that with the update whether it's in June of 2011 or June 2012.