The Last Guardian remains in developement
According to Fumito Ueda, team ICO head and creative director, The Last Guardian has been and continues to be in “earnest” development, but that Sony Computer Entertainment is more concerned with titles such as Puppeteer and Knack.
In an interview with Japanese magazine, Famitsu, Ueda had this to say:
“It’s under earnest development. However, SCE Japan Studio, who’s working on The Last Guardian, also has titles like Puppeteer and Knack, and those are only the ones currently announced. Those are taking priority right now.”
The Last Guardian has been in development since it was announced at the 2009 Electronic Entertainment Expo, and has seen very few announced updates since that time. Sony senior vice president of product development commented on the project, saying that it will ship “when it is absolutely ready.”
Whenever it is ready, the title will release exclusively on the PlayStation 3, but if the timing drags on long enough, it is entirely possible that The Last Guardian could see a release on the PS4 as well.