i believe theyre taking only the "core" elements of Dragonball, as opposed to making the live action equivalent of series, meaning itll have its own storyline and the characters will be different, i think its not a bad idea, to make it slightly different, else everyones gonna be expecting super saiyan lvl *** knows what
the fact is, DB had a sense of humor about it, this movie looks like itll be a cross between the fantasy of the chinese warrior movies added to action, which means its not aimed at the core fans of the tv series but more at a general audience, especially those that havent watched DB/DBZ or DBGT before, this seems more the prelude for things to come, like Batman begins or the Iron Man movie where the stories are planned out and characters are introduced, hopefully if its successful then we'll see more "DB" like stuff like super saiyans, vegeta, gohan(since apparently this is the movie where goku and chi chi meet, so technically they cant have had gohan yet) etc