Considering the vast scale of DBZ (big fights, huge detailed planets, hundreds of characters and NPC's, amazing effects) a PS3/360 release would make a lot more sense.
I think they should make a Wii-specific DBZ game rather than making them multi-platform. The Wiimote could emulate moves
accurately (none of that 'flick the controller up and thrust just-like-a-real-kamehameha-or-not' crap in BT2) while the next-gen consoles put their power to use for things like deformable terrain and maps the size of a country.
EDIT: According to the gamefaq's forum, the 150###!! on the scan refers to a roster of 150 characters and forms.
The PS2 version of BT2 had 129 characters and forms, the Wii version added six (Appule, Frieza Soldier, Pilaf-Bot, Combined Pilaf-Bot, Evil King Piccolo and Cyborg Tao) so that's 135. That leaves 15 new characters/forms. King Vegeta, King Cold and Nail makes 12 left. Quite frankly I thought they were clutching at straws adding Cui, Appule
and Frieza Soldier when they're almost identical.
EDIT2: Scan translation from GameFAQ's;
Muzusama said:
Sigh...as the top of the scan says "Super New Product" or something similar to it...
Dragon Ball Z Sparking! METEOR will feature about 150 characters and that the next couple issues of V-Jump will reveal the new characters that will be in the game.
Will be a Playstation 2 and Wii game with 2007 Fall release.