The Orlando Sentinel said 10 days ago "Both Universal Orlando and SeaWorld officials said they have new attractions in the works for 2007, including a new night show at SeaWorld, but just can't talk about them."
So I don't know if it means a replacement for Mistify or if it might be the newer Shamu Rocks night show (that's going to incorporate the 4 rotating screens put in for Believe) that San Diego is getting, or neither and a different show altogether. I would guess the Shamu Rocks show since it's cost effective to clone the show.