Kind of confused that since Obama is black he's expected to completely fix race relations. Most of the issues we've been dealing with have arisen from local levels. Not that the president has no power in that regard, but it's pretty limited, regardless of his race.
He could've ended the war on drugs, and stopped the militarization of law enforcement on all levels. Both would've done wonders for African-Americans. Those are two strongly federal issues which the executive has a lot of power over. Of course, you are correct in that Obama isn't really African-American (ethnically rather than racially.) His father was Kenyan and he grew up with his white family members, so he isn't inherently anymore well-versed on the issues that face the African-American communities today than any other non (ethnic) African-American president. You would think though that his wife would've pushed him in the right direction, as she is African-American (ethnically), but wanting to get reelected was probably a stronger motivation for him. Nevertheless, being black was a strong push in his campaign when targetting African-Americans, so there was a higher expectation for him than other politicians.