From other trailers, I like a lot of people were confused with why the movie is called karate kid, even though it's centered around Kung Fu. But if you pay attention to this trailer, you will notice they make the point that Dre knows karate, but is not the focus of it. The original Karate Kid focused around the title, making people understand he is a karate fighter. However in this new remake, you can hear that the bully's call Dre the Karate kid, making fun of him that he knows a martial art that does not seem to help him at all. The difference of each movie, is the fact that Karate Kid means a different thing in each movie. The original Karate Kid focused around Daniel who rose to the top through Karate, making him Karate Kid, the Karate legend. The remake Karate Kid focuses around Dre rising to the top through Kung fu, with the title Karate Kid as a sort of underdog name. If you pay attention again to the movie, you'll hear that Jackie Chan talks about how the movie is how a outsider is trying to fit in.
This concludes that what Karate Kid means in this remake, is a outsider trying to fit in because he is of a different ethnicity, and Martial Arts style; this being that Dre is Black and not Chinese, or a practitioner of Kung Fu. As Dre learns Kung Fu, he starts to fit in of course.
Maybe this will change your views on the movie, maybe not. Either way don't see the new Karate Kid as a simple remake, see it as a possible remake on what became a classic of a whole new meaning. The meaning being that in this era of a diverse world, their are many ways to fit in, such as learning Kung Fu.
P.S.: if i said anything that would probably insult Karate, i didn't mean to. Not saying anything like Kung Fu is better than Karate, just that people need to understand the difference of what the title Karate Kid means in this remake.