The thing that makes it an example of tokenism and political correctness rather than a laudable effort is that they are taking an established character, and changing it so it isn't the character anymore for the sake of PR.
It would be a laudable effort if they had instead decided to launch and properly write/support a new minority character, but that is not what they are doing. I am not a supporter of changing the ethnicity of well established characters, and there is no way to deny it being a politically correct PR stunt.
I would point a finger at DC Comics and it's "Wildstorm" universe as an example of doing things right. It didn't just take a bunch of established DC characters and decide "well in this continuity, we're going to modify all of the long running characters to be more politically correct", rather they created a whole new set of characters. Apollo and The Midnighter from The Authority are gay, one of them is even a fetishist who touches on that lifestyle occasionally for those who might practice it. Swift from the same team is Bi-sexual. In Gen-13 we have Sarah Rainmaker who is a Native American and a Lesbian. In Stormwatch we have Jackson King/Battalion who is black (and married to a white woman... Christine Trelane). It goes on from there.
Understand that many of these characters have remained in publication for over a decade now, so we're not talking about a fly by night occurance. Sure someone might sit there and say "well, I don't like these characters and I'm a member of the group of the group in question" but members of every "group" are going to dislike anything representing them, nothing is universally lauded. Obviously the continued existance of the characters, spin off universe, and titles proves that there is an audience... and one can compare it to other seemingly more well known characters who have failed to hold down their own book (or even a place in a team book) for any appreciable length of time.
I've felt for a long time that Wildstorm deserves more love than it gets, and have actually felt that perhaps playing with that universe/Jim Lee's work might be a better track for DC's media development. Rather than trying to make "Superman" more relevent and "appealing" for example and re-doing the whole character and his universe, perhaps playing around with characters that are already in that kind of universe (to an extent) might work. I could say more about it, but this is a side point.
The basic point here is that Spider-Man represents a very specific person, as opposed to a job description. Spider-Man is a white guy named Peter Parker. If Peter Parker dies, so does spidey. Trying to re-invent him is a mistake, especially when it's being done as a politically correct stunt. At least most alternative "Spider Man" ideas have involved a compelling story and a massive change in style/world/time period, in this case there is no real other purpose to this change other than to have a half breed minority as Spider-man to presumably get media attention, and attract minority readers with the news. Really, even Marvel doesn't have much to say about it except for the character's ethnicity, and that's a problem. At least with things like "Spider Man: Noir" and such the whole point was a total change in setting and style.
Really, Marvel needs to pull a "Wildstorm" and create and support some entirely new characters, and leave the established characters alone.