The blurb about the next kickstarted Onyx Path supplement, Cults of the Blood God, which is also due very soon, is that it will include a Clan referred to as Hecata. Their other referenced name is the Necromancers, so I guess these will be the Giovanni in actually.
This would mean that we have seen a continuation of one extra Clan per supplement so far:
Camarilla - Banu Hacim (Assamites)
Anarchs - The Ministry (Followers of Set)
Chicago by Night - Losambra
Cults of the Blood Gods - Hecata (Giovanni?)
Which still leaves us waiting for the Tzimisce, which could come out in a cute Sabbat book I guess and the Ravnos, which may need some work to make right (and have been killed off in canon in previous editions at least once before).
?