MacBook Air :: Edit Video On 13 Inch Ultimate?

I'm considering whether to buy a 13" base model (except 4gb RAM) or a 13" ultimate (2.13/4/256), which is stocked by my local Apple Store. The base model would be fine for what I do now (Pages, Safari, Mail, Skype, Netflix streaming). But I'm thinking of getting into video editing in the next year. A reviewer on Amazon wrote this about the 13" base model with 2gb RAM: "I've edited HD video on the unit (no problems), (though exporting is obviously much slower than on my imac, as to be expected, but editing and working on the footage was pretty much the same, it's only in exporting where you realize the machine is slower). If you do a lot of video work, or you render out animations a lot, you can use this machine to do your work, and your desktop to handle the heavy processing. Just store your files on a usb flash drive and xfer to your desktop to handle the render. I plan [more tests with] iphoto and imovie, (I want to try out the new features) as well as my regular workflow (lightroom / cs5) and final cut.".....