I like to check in every so often just to make sure I'm not missing out on any new projects, and I noticed today that the entry for the now-confirmed Dragonball Evolution sequel actually has some details on it.
Now, I have no idea where the information comes from, and it was apparently last updated in February. So I'm warning you now, take the info with a grain of salt. Or maybe a salt shaker.
That said, it lists the title of the sequel as “Dragonball 2: Reborn” (I've added it as an alias to the database listing for the film), and even offers a plot summary:
“With Piccolo joining Goku's side, the Earth becomes endangered by a evil Sayian [sic] known as Raditz whose goal is to destroy Goku.”
Again, I have no idea how accurate the info is-- it could be that someone just took James Marsters' declaration that he wants to do a film based on this storyline and extrapolated that it WOULD be. I've got a call out to Fox to see if they can confirm or deny the info, but I honestly kind of doubt I'll hear back. But if I do, I'll let you know.