It goes to show everybody, that it's not just the American fans that boo. It will take years before the casual fans learn the subtleties of the sport and grow to appreciate the ground game. Even at that point you will still have drunken fans that boo like crazy.
About 6 months ago I watched a Boxing match on HBO, the fight was in Germany, It was one of the Klitscho brothers vs some can from the US, who was the mandatory #1 contender. When the American fighter made his entrance the German fans were booing harder than any American crowd that I've ever heard. The guy wasn't trash talking, he didn't come out to some flashy entrance, he was basicly a no-name fighter. The point is, they only booed him because he's from the US.
Fans boo in every sport and they still attract new fans every year. Football, Baseball, Hockey, Basketball, Soccer, Boxing, MMA, you hear boos in all of them in just about every differant country(Japan is one of the few that is respectful, but they even boo sometimes, when they do it's usually justified).
Booing isn't goint to deter new fans, boring fights, poor marketing and bad descisions will. Most new fans aren't bieng influenced by the crowd while forming an oppinion on MMA. The announcers will have a greater impact on influencing new fans. Booing is human nature and will never stop in any sport(with the exeptions of Golf, Tennis and games like that).