I think this might just be the fact it's a new release (unless they just don't sell that many maxed out Airs). My work just got me a maxed out MBPr on Thursday. Was in/out in 10 minutes without reserving it online or whatnot (we're three doors down from our local Apple store.
Maybe that's a bigger store. Tacoma WA, my 15" RMBP was only available in-store in the absolute base, no customization models on the online store. Anything else had to be ordered in.
