There's definitely a double standard.
I mean, people were pissed (and still are) that a black man is currently playing Captain America in the comics. I remember when people were pissed that Rue, a character depicted as black in the books, was played by a black girl. It's a problem.
I think Idris would make a fine Bond. He has the acting skills and the good looks for it. It amazes that people are seething at just the idea of him playing bond, not even official casting, just an idea.