Amazon has launched their Appstore for Android devices. Aside from the eight step install process I think Amazon stands a better chance than just about anyone else in having a successful store and not just for themselves but for developers as well. Like Apple, Amazon has a well established music, video and book presence with millions of credit card holding consumers. What developer wouldn’t want to take part in that?
While the eight step install process on android devices is annoying today, imagine if Amazon produced a their own tablet with their store already loaded on it. I once said on twitter that for Android to really be as successful as iOS someone would have to take it and rebrand it as their own and build a great ecosystem around it. Amazon has that ecosystem, they just need a mobile platform to sell on.
If Amazon were to create that mobile platform, and it included a phone and a tablet, I think Apple would truly have a competitor to worry about.