We have posted in the past about the controversy surrounding the casting of the movie The Last Airbender. Many fans of the original series were upset that Asian characters were recast as White, with the main cast initially containing no non-White characters at all. This fits in with a more general lack of Asian main characters in Hollywood.
More recently, a different controversy about race and casting emerged when
African American British actor Idris Elba was cast as the Norse god Heimdall in Thor, though this character was always White in the comic book series.
Anthony N. sent in a video by MovieBob at The Escapist that discusses concerns over race in casting Thor and why recasting a White character with a non-White actor doesn’t have the same implications as recasting a non-White character with a White actor does: