There was an article quoted at
http://www.teleread.org/blog/?p=5578#more-5578 that indicates the Librie tools do work for the Sony Reader!
"To my great surprise, the content of my LIBRIe memory stick popped up in the Reader with no problems; it seems that the file/directory structure is similar, if not the same. The books are displayed just fine, yet in somewhat reduced fashion (judging by the embedded pictures). I am not sure about the interactive contents yet (like pop-ups), whether they would work, or not."