I didn't vote but am considering an MBA at some point. I have a 24" iMac as my desktop and would not personally want a notebook as my main computer. The MBA makes the most sense b/c:
I can't justify the price of a MBP b/c I don't need that performance
I wouldn't want a white MB and the blackbook isn't that much cheaper than the MBA
but mostly b/c of the weight. I want the lighter form factor and I think the 2 lbs less is huge.
So the MBA would be my 1st choice as a 2nd computer.