Didn't Cameron want to go into space so he could make a documentary or something? He wanted to film Mars and the other planets in 3D.
But for his next film, I don't care. I will watch whatever he makes next. The Dive does sound like an emotional film and wouldn't take too long to make and release but Battle Angel will be his next big thing I reckon seeing as he has got a script and some pre-production work for the film.
Cameron has said in a recent interview that he is glad he made Avatar first and not Battle Angel because he has learned a lot of stuff. He has said that it is difficult to have real actors interacting with CGI characters in 3D so he probably needs to perfect a method before doing Battle Angel.
I reckon that he will do The Dive, followed by Avatar 2 and then do Battle Angel because he would have perfected methods and available technology.