The Cybook doesn't support Epub yet.
It's been mentioned by Bookeen as being planned, but we don't know when it will come.
Calibre currently doesn't support outputting to a format handled by the Cybook, but some people from the forum (llasram and user_none, I think) are actively working on including this support.
I strongly suspect that in the future, Calibre's feed support will be available for Cybook too.
EDIT : a bit too slow.
a correction on my text above :
- llasram (as he mentioned in the post above) is working on Mobipocket generation
- user_none is working on Cybook support for Calibre (device detection and so on)
Last edited by Gaurnim; 01-09-2009 at 08:02 AM.