The movies are based on the comic, and the comic is based on an 1800's poem:
http://en.wikipedia.org/wiki/Little_Orphant_Annie
The poem contains four stanzas; the first introduces Annie and the following three are stories she is telling to young children. The stories each tell of a bad child who is snatched away by goblins as a result of their misbehavior. The underlying moral and warning is announced in the final stanza, telling children that they should obey their parents and be kind to the unfortunate, lest they suffer the same fate.
If playing a black character as Annie is at all racist, it's because we think of black people when we think of poverty right now. Chances are good when the comic and film were made, people thought of black people as lower than poor - so much so that it wouldn't be proper for a white rich family to adopt one, nevermind the possibility of a black family being rich and adopting a poor black child.
Honestly this it a tempest in a teapot.
The point of the story is that someone who is unfamiliar with wealth and good breeding is suddenly thrust into the lap of luxury.
Hilarity ensues.
Of
course they will play on black stereotypes. Is it going to be as blatant as Diff'rent Strokes, or played down as on Fresh Prince? Does it matter?
If it's good, it'll be good. If it's bad, it'll be bad. A bad actor may harm a good script, but the greatest actor can't fix a bad one, so let's just hope they've got good storytellers writing the script and see what happens.
It won't matter one whit what the original comic strip used if the movie is well done.