There is an interesting article over at Edge about the portrayal of Black characters in gaming. Though, it does read a bit too much like a University essay. Then again, it probably is.
I agree with everything the article says about Black characters in gaming being limited to already-accepted stereotypes such as Cole in Gears of War; though, the commenters on the thread point out several characters and games that deal with race a lot better (Left 4 Dead, Far Cry 2, etc).
But I think the article is narrowing what is a wider issue in gaming: every stereotype is overly simplified. Look at the only female character is Gears of War--or any character in Gears of War for that matter. Gaming narrative is still so young and so reliant on tried-and-tested formulae that I think many game writers still only feel safe with stereotypes.
That said, the exceptions are there, and are generally in the better games: Nico Bellic, Alyx (black and female!), and others that wil lsurely come to mind the second i hit 'post'.
Of course the only game to treat all colours and creeds equally is Geometry Wars.