The latest generation, Kindle Paperwhite, Kindle Scribe 2, Kindle Scribe 1, and Kindle and the upcoming Kindle Colorsoft, all have something in common. When you plug them into USB into your PC or MAC, they no longer appear as external drives. This prevents users from using file managers to back up their books or to sideload new books onto the Kindle. Amazon has also removed the download and transfer via USB option for purchased ebooks from the content page. This will likely prevent people from striping the DRM from the books and sharing them on piracy websites. This is not
Android is a massive value add. I can’t tolerate it for my actual phone, but it’s just an absolutely huge step up from the other ereader OSes.