Now that Google Music has finally officially launched on the back of iCloud, we can finally get down to the business of the online music business. Here's a chart form Huffpost Tech that outlines the features of the big 3 online music stores: Amazon MP3, iTunes and Google Music.
Who will win? I think that in the near future, iTunes will be hard to beat, but their market share will erode with time as Google Music gains some traction. Plus you can't beat the fact that they're the only one with an easy to use desktop app (which is what iTunes rally is - the front end to the digital music store).
We'll revisit this chart in a few months when the numbers are in to see how they stack up against each other market-share wise.