I've incorporated an EPUB Viewer (see thumbs). Very basic for now, but using xhtmlrenderer from Sun (Supports CSS 2.1) as LGPL. I'm trying to share source code at sourceforge this weekend.
New Version 0.9.137 with new action 'view epubfile' . See initial post in a while...
P.D. I belive this starts to be a little off-topic (epub viewer must go to another thread?)