AMN during E3, Ninja Theory co-founder Tam Antoniades said that Heavenly Sword is being planned as a trilogy and that the story of part two has been written.
"When we set out to do Heavenly Sword ... we wanted it to be a three-game story," he said at around the 11-minute mark. "We've had the story for the sequel for awhile now. Hopefully if this game is successful, then there's no reason why there shouldn't be a sequel and we'd very much like to go into that."
Given the hype for the title and our impressions playing it, Heavenly Sword is very likely poised to be one of the standout PlayStation 3 titles this holiday season. Just don't be surprised if you defeat the final boss and receive a cliffhanger ending.
[Via PS3 Fanboy]