According to a french site which has contacted Bookeen (
http://www.actualitte.com/actualite/...pport-Sony.htm),
the firmware with the EPUB support announced for today in the Weltbild Cybook Gen3 is a Release Candidate firmware, for Weltbild only, to allow them to compete right now with Sony.
The final Firmware update should come in a few weeks.
So we could imagine that Booken having to provide E-Pub support on April 30 and no later for Weltbild could have decided to focus on this customer first and release a firmware on time but without all the features (eg. Mobipocket suppport), and this could have delayed the final firmware version release...