Sony's making good on their promises, rebranding its "eBook Store" as "Reader Store" (see what they did there? Err...) but more importantly, changing formats from BBeB to ePub, like they said they would.
The big change happens this Friday, with all books downloadable in the open EPUB format only. The other news is that the Reader Library 3.1 software will also become available on Friday, bringing both Mac and PC support—head's up, Snow Leopard and Windows 7 users. [Sony]