There were rumors that Cypher was originally going to be part of the Dark Vengeance box set, and was dropped. If that was the case, rules and likely a model was already under way. Now, we have word that a codex author has just mentioned a supplement for the Fallen.
Please remember that this is not official, and thus remains a rumor until verified, or released.
via a Reader here at Faeit 212
Jeremy Vetock announced at games day that there will definitely be a fallen supplement coming, however we dont know if this is for DA or CSM.