It is unlikely that a new storyline will ever be created, however at the moment a series called Dragon Ball Kai is airing in Japan that is an edit of the original dbz. A new film was also released not far back (animated, not the poor live action one).
There's Dragon Ball Kai and the 3rd and 4th special of DBZ still to be dubbed.
3rd special is Plan to Destroy the Saiyans taking place after Broly but before the Cell Games with the main villain Dr. Raichi who is a Tuffle.
4th special is Yo Son Goku and Friends Return where we meet Vegeta's younger brother Tarble.