At the moment director George Miller is still working on his new movie "Three Thousand Years OF Longing", but the next project after that is already fixed, namely Mad Max - Fury Road. In the past there were some financial problems with this project, so the fifth offshoot of the series was often postponed. However, this now seems to belong to the past, because as the director announced, there was finally an agreement. Miller explains that he's already in the middle of preparation, that the story of Mad Max isn't finished yet and that another Mad Max part will surely follow. The director has already stated the latter several times in the past, allegedly even the script for the sequel is already finished.
However, we have to wait quite some time until the shooting starts, because first of all the shooting for "Three Thousand Years OF Longing" is scheduled to start in March next year.