I thought about this when reports of Google music started to appear and the way Amazon sees it is completely my point of view. If it is my content that I upload to that service, then it really isn't Amazon's duty to care about licensing deals. The analogy to an external harddrive mentioned in the article explains this very well. You could even go one step further and replace the external harddrive with your own webspace to make that analogy even more similar to Amazon's service: Imagine you upload your music to your own webspace to be able to listen to it wherever you are. Not very practical, but there's no way one could argue that there have to be any additional fees involved. This shouldn't even be news.
So when Google has to negotiate with record labels this tells me that users apparently don't simply have upload their media collection. There have to be more features, similar to former lala.com maybe. Otherwise Google shouldn't even feel the need to contact any record labels. After their music is bought it's none of their business anymore. At least that's my opinion.