I share the desire to permanently own media. Amazon have been selling music as DRM-free mp3 files since 2008, though, so that option is already available from a legal, mainstream online shop.
I'm glad that Amazon sells DRM-free MP3s (although I imagine they only did it to remain competitive with iTunes). They don't do it with their eBooks, however. Any time I buy an ebook through them, the first thing I do is download it to my PC and strip the DRM via Calibre so that I have a DRM-free version should Amazon ever decide to yank the original again.