Fans of ' The Expendables " have been clamoring for a sequel since the final round of alter kocker gunfire went off last summer. Now it looks like they'll get their wish-- but without Sylvester Stallone behind the camera. The follow-up movie is a priority at producer Millennium Films, where it's being developed by Stallone, the creative force behind the original. But Stallone, who both starred in and directed the 2010 summer hit, isn't, at the moment, planning on helming the new movie. Instead, he's been meeting with directors to tackle the sequel, said a person who was briefed on the project but was not authorized to speak about it publicly. The script for the new movie has been written by David Agosto and Ken Kaufman, the latter of whom counts the Clint Eastwood adventure "Space Cowboys" and family comedy "Curious George" among his credits, said the source. (Stallone co-wrote the script for the original with David Callaham.) A sp