I was at the flea market today and saw some kids at a booth playing this. I was really impressed with the graphics, and after they left I got to play the game for about ten minutes.
Like Teenage Mutant Ninja Turtles, Dragonball Z just lends itself to cell shading. The game looks really, really good. The fighting system seemed overly simple (maybe there's a more advanced mode?). one button punched, another kicked, and another just seemed to continually shoot fireballs. It didn't seem that tough to stand around and blow people away with fireballs all day long. The X button blocked. R1/R2 seemed to do different attacks depending on how far away you were from your enemy. One of the L buttons did some sort of power up.
There was also a big adventure mode, where you fly around the country side, looking for fights and people to talk to and stuff. It was pretty fun. After you beat people you get what look like Yu-gi-oh cards with different abilities and such.
This isn't an in depth review by any means, as I only got to spend a few minutes with the game, but from what I saw, this looks to be pretty cool!