Next DBZ might star Vegeta and Goku's Mom to be Revealed

During an interview with Akira Toriyama he stated that whenever Toei starts making a sequel to DBZ: Battle of Gods, he wants to make Vegeta the main focus and that he plans on revealing and detailing Goku's saiyan mother within a few months.

It wouldn't necessarily be about his past. The part about Goku's mother is a project on it's own for now. Whatever the next movie is, it'll most likely be a continuation of Battle of Gods. I believe Toriyama said something along the lines of that Vegeta deserves a turn to have the spot light, because his character had the most development in the series.