Ignore anything you read elsewhere — the game being released in the US by Atari under the name “Budokai Tenkaichi” is indeed the game “Sparking!” being developed in Japan by Spike for Bandai.
IGN has some new information (including images and movie clips!) concerning/from the game. Look for upwards of 60 characters, including all five of the Ginyu-Tokusentai.
I do have a bit of a problem with the IGN article calling the game “Budokai 4”. This is a brand-new game being developed by a completely different game developer (Spike vs Dimps) with a completely new game engine, and as such, really makes no sense to call it “Budokai 4” (note that is also not being called “Dragon Ball Z 4” in Japan, or anything like that). Regardless, check out the article for some screens and videos (from the Japanese version, no less!).
We also have some other gaming news, mostly for all you international fans. Poor little “Sagas” is coming out over in Europe in July, and you will also be getting “Advance Adventure”, which is up for pre-order both on Amazon UK and Amazon Germany.