The DBZ Burst Limit demo is up on Xbox Live and the Playstation Store. I'm downloading it right now, I'll comment on it later.
EDIT: Eh...I thought it was ok. Graphically it looks alot better than the Budokai or the Tenkaichi games and it feels a bit more fast paced. Each fight has "Drama Scenes" that you can unlock by doing certain requirements and theres a bunch of objectives too that you find out after the fight to get a ranking (there's a bunch to do in the course of one fight...)
The demo only has the Goku vs. Raditz fight and Yamcha vs. 4 Saibamen. One of the "Drama Scenes" that I got was doing Kamehameha against Raditz and then a scene pops up with Raditz talking about how Goku can power up. The other one I got had Piccolo coming in and kicking Raditz in the face (I think I got this by letting Raditz beat me up for a bit). I kinda wish they put in a couple of more fights or maybe even at least Goku vs. Nappa so you can use the Kaio Ken transformation (for PS3, R1 is your transform button).
The game only appears to go to the Cell Saga. That's the demo anyway.