Maybe. But so are all the headlines about Amazon. Yes, Amazon beat Apple and Google to the punch on the media locker, but the extent to which that is relevant is questionable. Apple sells 70% of the digital music in America compared to Amazon's 12%.
It's good to see Amazon getting in there and releasing forward-looking products, but it is also important to realize that they still have a ton of catching up to do. If Blockbuster released an online video locker product I don't think it would dramatically affect Netflix.
Point simply: Kudos to Amazon for getting their first. Not sure it's going to make much of a difference seeing as Apple's media locker is coming out in the next few months (as is Google's apparently). Customers are sticky to their music stores.