Hi,
Yes, development of Sigil is back in full swing. FYI, Sigil 0.8.3 should be released shortly (this week?) with an upgrade to Qt 5.4 and lots of bug fixes and stability improvements.
Heavy development work will then begin on transforming Sigil to work with both epub2 and epub3 equally well. We will be replacing Tidy with Google's gumbo-parser, making flightcrew a plugin, bundling Python 3.4 into Sigil and using it in an embedded fashion, support tor html5, etc. This work will go on in an all new trunk.
If anyone wants a leg-up on the upcoming 0.8.3 release and its changes, see
https://github.com/kevinhendricks/Sigil and read the ChangeLog.txt there.
All of this should be moving into user-nones tree shortly.
KevinH