Square Enix has confirmed that RPG Star Ocean 4's official title is Star Ocean The Last Hope.
The company gave the details at the Microsoft's ongoing Xbox 360 RPG Premiere 2008 event in Tokyo.
Update: The issue of Star Ocean’s platforms has been clarified on IGN. From the site:
Square Enix producer Yoshinori Yamagishi cleared things up during a roundtable interview session that followed the press conference. Asked if the game is 360-only, he said, “We cannot announce anything on that. We can say that it will be released first [on the Xbox 360]. Whether we’ll release it on the PS3 is undecided. We may release it, we may not.”