My Girlfriend, her two boys and I were exiting seeing Avengers 2 (No spoilers) which was just great. The ten year old was kicking a chair through some of the talking scenes, but on the whole we all loved it. As we're exiting he sees the poster for Fantastic Four, and can't help but notice the elephant in the room. As any ten year old should remarks, "Why is Johnny Storm black?! That's stupid!" As an older school nerd having had this conversation for some time involving the re-gendering and/or race-bending of historic characters I was kind of at a loss to explain. All of the long discussions of "white privilege", "diversity", "don't be a bigot", etc sort of melted in the stark reality of a ten year old demanding to know how a White person becomes Black.
My girlfriend and I discussed expanding audiences, and executive decisions and a lot of things that are like the second to last broadcast of the Howard Beale show in the movie Network: long-winded and totally sucking the fun out of/breaking the suspension of disbelief. In retrospect I could have said the movie universe is an alternate universe, and I feel that he would have been satisfactory because that same answer is to me. Johnny Storm being Black, or Iceman being Gay isn't offensive because I'm a bigot (as far as I know) it's because there's no chain of causality. Aside from Michael Jackson or Little Kim there's not a lot of instances of Race-bending. White washing perhaps, but that's something else entirely. Perhaps Nick Fury or Johnny Storm being black now is "black washing"; solely for the purposes of new markets couched in the invulnerability of diversity.
A friend of mine and I discussed the whole gamut of what is canon, "gate-keeping", white privilege, etc and got as far as two white guys can get. I always feel like a hypocrite because I identify as a liberal progressive yet here I am coming out against these sorts of things because they seem to be arbitrary or out of left field. I don't care if an alternate universe version is black, female, gay, or what have you. Even in the main universe Thor became a frog, so... what does that say?
There's a concern that this "diversity washing" is just the foil embossed cover of the twenty-ten's. It's a gimmick. Personally I think it's brilliant when Ms Marvel has a protege who's Muslim because you're starting a new mythology that can grow on it's own. Robin became Nightwing, Bucky became Winter Soldier, Powerman became Luke Cage. Protege characters actually have the opportunity to evolve into their own character. Unless, of course Falcon becomes Captain America in which case the role always reverts back to the original formula. I'm actually all for Falcon graduating, but that seems to be the trend (examples abound; US Agent, Winter Soldier).
Eventually at the end of the discussion with my friend Cedric and my GF's son ended on the same note. Whether something becomes new canon or not depends entirely on whether it's done well or otherwise. Wait for the new movie to come out, and if it's enjoyable then good. If not... (I'm looking at you The Amazing Spiderman 2) then we know what happens to canon that is god damn horrible, because it's actually shittily done. It gets stowed away in the circular file drawer of reboots, revisions, etc along with The Clone Saga. Ugh.