Incredible. The one time I've been into an Apple store there wasn't anyone available to talk to about a Macbook Air I was seriously considering buying, and eventually after drooling for a while I got cold feet and wandered out of the shop...
The ability to buy anything under $100 using your iPhone and the Apple Store app, without talking to anyone, should help with that a little, as people learn about it. Especially during the holidays.
I think you can also use the app to pre-order things, so that they are ready to be picked up when you get there.
No wonder they reversed the decision!