here is how i feel about the whole race issue. bare with me, it's quite a rant...hehe
first let me start off by saying that i'm a Filipino American. depending on who you ask i would be considered Asian or Pacific Islander. i have Chinese blood in me somewhere but i was born and raised (mostly) in America. so obviously this is a biased opinion, but i try to be practical about my views even though it's a tough balance between practicality and art.
which brings me to the beginning of anime early last century. many people don't know this but a lot of styles from early anime resembled early american cartoons like looney toons and disney. from this sprung the popular and clich'ed big eye look that's so popular in most anime since then. a lot of people think that the Japanese draw big eyes in cartoons because of some sort of envy complex, but it's really because big eyes just work better with expressing emotions.
anyway, anime kept evolving until eventually Akira Toriyama came up with the idea of Dragon Ball. he took a trip to China and read an old Chinese folk tale called "A Journey to the West" and when he returned home he was inspired to make a manga based on that folk tale. Akira took Sun Wukong, the monkey king from Journey to the West, and made him the main character, Son Goku, for Dragon Ball. he also took the idea of sutras and refashioned them into dragon balls. so he based his manga on an old Chinese folk tale.
that being said, i think it's clear that Akira originally intended Goku to have Asian-ish features. i would even go so far as to say that he DID have Asian features. in his normal form Goku's hair is long, straight and black. his eyes are black also. his NAME is a Japanese name and his gi is shaolin (Chinese) inspired. not only that but he published the manga under the Japanese magazine, the Weekly Shonen Jump. it eventually got so popular that it spread to the rest Asia and helped start a new trend in Asian hairstyles. in the mid 90's it reached American television. so basically Goku was made by a Japanese, inspired by a Chinese folk tale, published in a Japanese magazine, originally aimed towards Japanese and Asian readers.
with all that in mind, i never expected Hollywood to make an adaptation of Dragon Ball with an Asian (or even half Asian) as the lead role even though i thought it would be a great opportunity to catapult an Asian with the potential of becoming leading man material into stardom. i tried to keep realistic expectations so i didn't think they'd cast an Asian for Goku and i knew there were going to be a lot of changes, most of which would probably do more harm than good. so i was at LEAST hoping for whoever were to play Goku to look and act like him, regardless of race. however, my want for an Asian actor to play Goku comes from the fact that i have Asian ancestors, know the origins of Dragon Ball, and most of all.....i believe that if a film adaptation is to be done, that you should ALWAYS goto the source material for inspiration and guidance. in this case, that would be the original Dragon Ball cartoons and manga.
that brings me to the culture clash, where many Americans think that Goku is supposed to look like a white guy despite the Asian inspired settings. Goku is raised by someone who's basically Chinese, has a Japanese name, and Asian clothing but for some reason many Westerners think he's supposed to look white. sure it's stereotypical for an Asian person to have an Asian name, wear Asian clothes and have Asian mentors but it honestly wouldn't be stereotypical if it weren't so common and true. the more you take away from a culture, the more generic it feels and that makes having a white guy play Goku seem less legit in my eyes. a Caucasian ninja doesn't feel as authentic as an Asian ninja and i feel that a white actor as Goku doesn't feel as authentic to the Asian inspired surroundings and themes of Dragon Ball.
to wrap it all up...again, i never expected Hollywood to cast an Asian as Goku nor did i really have a problem with it. i honestly just wanted a capable actor, but i feel that Goku was always meant to look like an Asian based on the fact that he is a character with Asian features, ideals, and most importantly...origins.