We don't have a whole lot to go on here, but according to a user on the NeoGAF forum Capcom has recently filed for a new trademark connected to the Onimusha franchise. Apart from this we know about as much as we do of Jon Snow, but naturally fans of the series are already crossing their fingers for a continuation or reboot of the series on newer hardware.
The latest entry in the franchise was Onimusha Soul, which is a browser based game released in 2012. Before that we saw Onimusha: Dawn of Dreams for PlayStation 2 in 2006, the fourth entry in the series (spin-offs not included). The first game Onimusha: Warlords, was originally released in 2001 on PS2 (later on PC and Xbox).