The creators of Uncharted: Golden Abyss and Syphon Filter have an action-adventure game in development for PS4, if a senior UI artist's LinkedIn profile is to be believed.
The artist in question is Rick Stalder, and his current job reads, "Sr. UI Artist at Sony Computer Entertainment America; Bend, Oregon." Under the Experience section, he elaborates that he is currently building the UI on an "unannounced action/adventure (PS4 ONLY)."
There's little else to go on right now, but it stands to reason that Bend Studio, who has been quiet since the release of Uncharted: Fight for Fortune, would be hard at work on its next title. The "action/adventure" bit is especially interesting, as that genre disclaimer could reasonably apply to both the Uncharted series and Syphon Filter.
Has Naughty Dog given Bend Studio its blessing to make a PS4 Uncharted sequel? Will Syphon Filter make a glorious, next-gen return? Stay glued to PSU for details as they break.