Fumito Ueda's input is pretty much done, and he has no control over when the game will be completed.
If you've spent any time in this hobby at all, then you know Fumito Ueda's work, even if you don't know his name. Ico and Shadow of the Colossus are incredible experiences, the kind of storytelling that really leaves its mark on you, and for the last few years Uedea's meant to have been working on The Last Guardian, a very long awaited Team Ico PS3 exclusive. Or perhaps it'll be a PS4 exclusive now; who can say? But Ueda knows things have taken far too long and, in an interview with Edge magazine, he says he's terribly sorry to have kept fans waiting all this time.
He doesn't work for Sony any more. He decided to go freelance for personal reasons; he didn't feel at all happy about the direction his career was taking. He won't - or can't - go into detail about his departure, but it seems clear that Sony wasn't pleased about his decision. He still works with Sony, on The Last Guardian and other projects, and he says his Last Guardian work is mostly complete.
"But," he admits, "the details of when, where and how it will be completed are beyond my control." Far, far beyond it. Back in February Ueda claimed that Sony was about to make a Last Guardian announcement, but it never came.
Back in August, Ueda told Famitsu that Puppeteer and Knack took precedence over his Last Guardian, and Shuhei Yoshida has claimed that Sony's just waiting for the right time to re-introduce the title. Well, Puppeteer and Knack are out, and the PS4 release is well under way. Maybe that right time will come soon, but I wouldn't hold your breath waiting for it, if I were you.