Lots of valid perspectives here. Just ordered my Air, will have it tomorrow. I'm not regretting the purchase, despite the 1GB RAM. I know the OS runs lean. My Air will run well on 1 GB. I know a faster CPU and higher memory bandwidth will help iOS reload apps and app states from flash memory back into RAM quicker, as well.
All that said, SURE I wish it had 2 GB, and am bummed that it doesn't. If there's one thing us computer geeks know, you can never have enough RAM. And yes, if you look for the effects of low RAM on the iPad Air, you will see them. But I bet most casual users can't even tell, because iOS hides it well.
Anyway, it's not enough of an issue to ruin my experience. For some, it may be.