Dionne Galace restarted the serial novel, for me at least, with the series on her blog. Lilith Saintcrow, an author with Orbit who pens the Dante Valentine Series and the new Jill Kismet Series, is launching her own free serial novel: Selene.
From the press release:
Set in the world of the Dante Valentine series, Selene expands on the Saint City adventures of Selene and Nikolai. New chapters will be posted every Monday, Wednesday, and Friday.
The serial will be available on Lilith’s site at http://www.lilithsaintcrow.com/selene/
You can subscribe to the rss feed here: http://www.lilithsaintcrow.com/selene/feed/