GigaOm's Om Malik has a post today about the overwhelming success of the Apple App Store and how it has fostered a look a like "me too, me also" approach by many of the other handset developers like RIM, Nokia, Android who have use the app store model as a way of working with developers.
For developers the App Store is the equivalent of a branded gasoline station. It is not yet WalMart or Amazon, the two brands that best come to mind as "super markets" or "hypermarche" as the French say. That means your selling to a very niche audience, a specific product for a specific device or platform.
None of the app stores yet have an Open API (that I know of) that lets you "stock" a virtual shelf and provide an all in one location for "mobile" apps the way a Handango can offer downloadable apps that can be installed onto devices, but not as easily as the app stores allow for with their download marketplace model.
I have to believe that Amazon or WalMart would both relish the opportunity to become the cross platform "app store" retailer so people (or families) with different device platforms could all run compatible software, purchased in one place. But alas, I also fear that co-mingling of the apps would be a challenge for the current platform providers, as they want to own the experience end to end. That said, history has shown that we can go from direct selling to the middleman approach quite easily so this also is really more of a "when" than a "would they ever" in my mind, especially with Amazon and WalMart already selling mobile phones and MP3 players and iPods.
Now, back to the Om post. The reason Apple has won the early rounds of the App Store wars is simple. No company understands consumer behavior better in technology. Period. While others may study it as closely, Apple lives by a philosophy of KISS (keep it simple stupid) and does not release something that isn't easy to use. They hide the hard stuff and make it easy for the user. Ergo, why they have a "Genius Bar" at Apple Stores. There the things the average user cannot do, get done. Can your above average user with the right tools and information do what's done at a Genius Bar? Yes, as the really hard work gets done in the back room or is shipped out to a repair depot. There again, Apple understands consumer products better than the rest. (Have you ever seen an on site repair done on a PC at a Dell sales location?)
Next is the whole process. Apple not only released an App Store, they created a whole cottage community of developers, gave them an event (The Apple World Wide Developers Conference) and made the developer stars in their own world. Again, no one else has taken the approach of end to end, cradle to grave, like Apple.