It's sort of a Catch 22. I believe audiences have shown a willingness to embrace "ethnic neutral" films starring a person of color, assuming this person is already proven (Will Smith, Denzel Washington, Forest Whitaker, etc.). The problem arises when you consider the fact that Hollywood seems unwilling to hire minority actors outside of those who are already established. I believe we're starting to already see the effects of this, for example, how many big name (Hollywood) minority actors can you name that have come onto the scene within the last decade? I can think of a few, but most a lot of them seem to be from over seas.
I think the industry is actually starting to regress, in terms of representation, the 70s to 90s seemed like a much better time for minority actors within this country. For the most part, we seem to be living off the actors who came to fruition through out that window in time.