Picked up one at a Microsoft store in san Diego and the store was pretty packed. The sales rep said they sold a lot of them today. When I was there I saw three purchases in about 20min not including mine. Hopefully this device takes off.
They had way too many "event staff" at the Microsoft store. I picked up my two Bands and 10a and at that point, there were 7 of us purchasing at least two units each. The Scottsdale store did get another shipment later in the morning and I have heard they have not sold out or are close to it although I heard the water bottles, hats, etc. are gone.
Got mine here in Boston. I got squat with it. The staff at the Boston location is terrible, though, so I'm unsurprised that the complete shopping experience wasn't being executed.