Well, a basic report from Katsucon from those who were there. My sister was nice enough to pass out the literature that was shipped up there and got to talk with a lot of people. In conversations, she found that a lot of people there had serious reservations about the film in regards to race. There were some who saw the Super Bowl spot and thought it looked good, but the race thing was unavoidable.
From her, I know that she convinced at least three people to swear off the movie completely. They hadn't been following the race thing, but once they heard about the changes to the story all got a lovely shade of "WTF?" crossing their face. For two of them, the big turn off was the changes to the martial arts. He was mentioning about how cool the water bending looked with the tai chi moves and when he learned that it wasn't going to be tai chi, raised an eyebrow. He then listed off the other martial arts and when he learned that they were changed and that that M Night thought that martial arts weren't an important element of the story essentially gave the movie a "well screw that" rating.
M Night himself also seems to be turning a lot of people off.
So, good results. I think our best weapon is information and in the lead up to the movie, the studio will be giving us all the ammunition we need.