God, you all act like the DBZ mythology is sacred or something. It's like anything that's brought to film from a different medium. There's a novel (or manga) and there's a screenplay. Dragonball is HUGE, and took HUNDREDS of episodes to create the mythology. If we brought in every character exactly as they were, then 3/4 of the movie would be devoted to the introduction of a new character.
I don't care what a character is "meant" to be. I've seen the original Japanese Dragonball live action movie, and it starred a child and included an actor who looked almost exactly like Roshi. Hell, it even had a weird-ass attempt at including Puar (the part played by a parakeet :\). And what hapenned? The movie was so silly even in relation to the source content that it was laughable. Laugh out loud laughable. Sure, Roshi was a spot-on match to the anime character, but the whole thing portrayed THIS faithfully (aside from the parakeet malarchy) just felt so wrong.
And how about this guys? Maybe like Gohan (the son, not the grandfather) Goku is only JUST starting high school, which explains why he's looked at as an outsider. Perhaps his innocense HAS been preserved, and maybe he really DOES know a little bit about fighting. We don't know any of the minute details.
What's my point? My point is you're all reacting badly to this only based on the very little information we really have on the film. What did we just learn here? Piccolo IS going to be green, right? The last few weeks that's half of what everyone here was pining over. And it turned out to be a false alarm! Why can't the same be true for some of the other things you hate it for?
I mean really, I don't think Ninjas kill Gohan to steal his social security check. Obviously it's part of Piccolo's plan to eliminate any possible threat, and Gohan is a great fighter. Goku was found in the woods, and he was probably raised there, and naturally, he probably learned a thing or two abought fighting from his surrogate parent. Do you really think they're going to put Goku and Gohan in an apartment or something? The people in charge of this aren;t as dumb as you think they are. The reason behind Piccolo's skin color has proved that to me. These guys are putting thought into this, I can tell. Will it win an Oscar? Nah. Will it be the biggest grossing film of 2009? I doubt it. I'm not saying I think the film will be utter brilliance, I'm just saying I don't think it's going to be utter dog**** either.