it was this post including your current setup upon which I based my comments.
to clarify what I meant:
if you don't do much graphics intensive stuff, and you've stated that even 4gb 'would not be enough for my applications'; and you currently have a MBPro with 6gb of memory - then:
a) you must be running some heavy duty apps that require top notch cpu/gpu with lots of memory.
b) a MBAir will not fulfil your requirements.
so that said, if I upset you I apologise for I must be missing something here;
or else you are rather sensitive to being misunderstood for some reason