It appears that Apple is now allowing walk-in customers purchase the iPad mini with Retina display. Since last week's odd soft launch, customers could only get a new iPad mini in an Apple Store if they ordered it online and then opted for Personal Pickup due to supply constraints.
So far it's looking to me like it's not as constrained as everyone thought it was going to be. Unless when it gets closer to the middle of Dec. when everyone is going crazy buying gifts the big push will hit. I can just say having now enjoyed mine for the past 2 days it is an amazing little device and I LOVE it!