Listen up Sony Reader owners: you’ve got three days to change your ways. On December 11th, the eBook Store from Sony will be renamed the Reader Store with a new URL to prove it. In addition to a new store layout, the change also extends the open EPUB format to Sony’s entire inventory of eBooks. In fact, any new electronic books will only be available in EPUB which helps explain the motivation for Sony’s PRS-500 trade-in program. As such, we can say goodbye to Sony’s proprietary BBeB (“BroadBand eBook”) format which goes the way of ATRAC (outside of Japan, anyway). Sony’s also making its Reader Library 3.1 software for Mac and PC available on the same day with support for the imminent Reader Daily Edition launch and compatibility with Windows 7 and OS X Snow Leopard — how timely.