Sabat is reprising his roles of Piccolo, Vegeta, and Yamcha. He mentioned that he'll no longer be doing any of the Ginyu Force members (he originally did Recoome, Jeice, and Burter), which is good since that allows for more diversity in the voice cast. But here's the biggest news: There's going to be a new Frieza! Yes, you guys read that correctly. And this time, he's being voiced by a MAN. Finally, Frieza's character will be done justice
.
Here's a portion of an interview between Chris Sabat and Sean Schemmel discussing the aforementioned details. Definitely worth checking out.
http://www.youtube.com/watch?v=mQimwco0qo4