We are working on several fairly large projects over here at PayLoadz. One of which is investigating Amazon Web Services (AWS), more specifically, the Amazon Simple Storage (S3) platform to host the files we deliver for download. I just finished emailing Will Meyer of cruxy.com as I came across their site and saw they were using the platform (similar service to ours) to deliver their content. He had nothing but positive things to say about it.
The move to the system will take a few weeks at least, probably more with all of the other things we have going on. It will remove the existing FTP functionality from our sellers which a lot of people use to put their files on our servers. Will mentioned there are likely clients to do this already- we'd just have to provide them to our sellers or roll our own. I like the idea of offloading such a substantial risk area of data loss off on Amazon. Backing up terabytes of data is not easy when working with RAID storage systems.
A lot of people have forgotten about Amazon in terms of a cutting edge company and just view them as a storefront. However, they have released a large set of tools that are particularly interesting for developers. Tools that they use themselves. IMHO, I can see a lot of potential growth for Amazon in this direction, outpacing their traditional sales growth eventually.
Cheers,
Shannon