Details on Syphon Filter 4 were apparently revealed by the official PlayStation website last night, before being taken down again.
According to the description, the game will be a sequel to the Syphon Filter: Logan’s Shadow PSP title. It will revolutionarise the aspect of stealth in games by using the latest engine developed by SCE London.
According to the poster on GameTrailers it will be released in Q4 2012 for Playstation 3 system.
Expect more info at the E3.