While in NYC last week I was walking past the Best Buy Mobile store near 45th. I had seen one on my last trip and made a mental note to stop in the next time I got a chance. So this time I did. I was glad I had seen a Car Phone Warehouse when I was in London last which provided me a good understanding of what Best Buy is trying to bring here. The store in NYC (I believe there are 8 pilot stores in Manhattan) was very similar in look and feel to the stores in the UK. The selections were divided into unlocked, carrier specific, prepaid and accessories. Accessories were certainly a huge part.
For someone who wants to shop across carriers I think the store is pretty good. For someone who is looking for unlocked phones the selection was pretty light and certainly that is primarily driven by the subsidy model in the US. In general I hope that they succeed and help bring more selection to the market but if I were a betting man I am guessing that it's going to be a tough haul.