Very nice
Has user_none reconsidered and will he keep maintaining Sigil, or are these "just" bugfix releases from now on?
While I would still like to see the/an EPUB-editor in Calibre (and be glad to help if I can), I'd be happy with continued bugfix-maintenance of Sigil as well. More options is better; there are no other "pure" EPUB-editors around, as far as I know. Most of them are word processors with (some) EPUB-capabilities.