"Amazon's reading apps now gives you the option to read your Amazon ebooks on virtually all phones, PCs, Macs, iPads, iPhone, etc. The old arguments of "What is Amazon stops making Kindles?" or "Why should you have to buy a Kindle to read ebooks from Amazon?" become largely irrelevant. For average (non-techie) readers - does DRM really matter anymore if they can read their books on any or all of their digital devices?"
Yes, you can read Amazon ebooks on about anything except the device you most want to read them on...your own, non-Kindle ereader! I don't really care if I can read it on my phone, toaster oven or my dog's backside. I want it on my Kobo!
When it came time to commit to a VCR format ages ago, I had a choice: Buy Beta tapes that only played on Sony Betamaxes, or buy VHS tapes that played on everybody else's machine. I think it's telling that Sony has gone with the more-nearly-open ePub format. Maybe they learned a hard lesson that Amazon hasn't.