Details here. Apparently it's not a continuation of the last two films. It's being directed by a guy called "mink", which instantly screams "quality". It sounds as though we've got a long wait for this. Probably a good thing.
“First things first, is the way these larger projects need to be done," said mink. "It is still in the business stages but once that is squared away all casting options will be explored along with the continued development of the best story line.”