Firstly, I have only seen the original Karate Kid in bits & pieces on television, once. For me this version  is as fresh as any other movie as I have nothing to compare it against.
So, this is a story of a 12 year old boy - Dre, played by Jaden Smith, who moves to Beijing, China from Detroit, U.S.A. due to his mother's job [played by Taraji P. Henson]. The movie narrates his struggle in adjusting in a new environment which is made harder due to the cultural and language barriers. To make it worse he makes an enemy with a class mate [who also happens to be excellent in Kung Fu] on the first day he arrives! Dre luckily finds support and guide in the maintenance man of his apartment building - Mr. Han, played by Jackie Chan [of course!]. Mr. Han teaches him the art of Kung Fu, which goes beyond it's martial form.
Jaden Smith is absolutely his father's son. This 12 year old boy can act! and very well at that. He is surely going to grow up to be a lady killer. Jackie Chan is pretty good too. No goofy acts in this one. Absolutely age appropriate, is what my husband had to say for his choice of role in this movie. Besides, the movie is set in China so I do not see anyone else doing this role better than him [and attracting the audience, like he does!]. Taraji doesn't have much of a role in the movie but when ever she does arrive on the screen, she makes her presence felt. Nonetheless the movie belongs to Jaden Smith & Jackie Chan, primarily!
In the cinema the children were cheering and clapping for Dre while he was competing for the Kung Fu Tournament. It was an exciting experience to sit among all the children and watch this movie. My only vexation was that it was a tad-bit dragged in the middle. It could easily have been about 15 minutes shorter. But I am not complaining and that doesn't make the movie any less fantastic. The movie is very well made and would appeal to all ages [My Mom loved it!]
Bottom-line - It's good. It's really really good!
P.S. I do not wish to give away too much of the story, for is definitely spoils the movie for those you are interested in the suspense. Therefore, I try and only share my opinions about everyone's acting and general view about the movie.
This is what I wore to the movies!
Dress - Wild Orchid [Delhi, 07']
Belt - Gap [10']
Shades - Fendi [07']
Shoes - Nina [07']