Job listing and a facial mo-cap credit suggests Sony Bend is working on a sequel.
Kotaku reports that Sony Bend is rumoured to be working on a new title in the popular Syphon Filter series.
Two facts point towards Syphon Filter 5's development. Firstly, Sony Bend published a job advertisement earlier this month seeking a game tools programmer with experience on the PS3 and Xbox 360.
Secondly, a Syphon Filter 5 credit over on PCB Productions, a digital content studio in LA. The credit stated, "SYPHON FILTER 5 - (Facial Mo-cap) - PLAYSTATION3- SONY BEND".
Sony Bend has been the developer behind the entire Syphon Filter series and more recently has been working on Resistance: Retribution for PSP.
We're currently waiting to hear back from Sony, but don't expect anything more than the typical "rumour or speculation" response.