I knew that news post would come up when I heard this story on NPR yesterday, and I just wanted to say that I advise people read the interview with Lang Lang before making their own conclusions.
You can read the transcript here: http://www.npr.org/2011/01/24/133187969/Pianist-Lang-Lang-On-His-Controversial-Music-Pick
In all honesty I believe this was totally harmless.
For those who tl;dr, important quotes:
Mr. LANG LANG: I feel very sad. You know, I very sad. And, you know, and I must say, disappointing. Because, you know, as a person, what I'm trying to do, and what my missions are, you know, making music. And, you know, I'm very honored that people inviting me to play in those great events and to connect us to classical music and to music, to Chinese music and to American music, to, you know, to world music. And once, you know, people use it as a political issue, that makes me really sad because I am a musician. I'm not a politician.
BLOCK: The song that you played, in the movie, in the "Battle on Shangganling Mountain," which came out in 1956, it is a very nationalistic song and it...
Mr. LANG LANG: You know, I never know about that movie. I just learned it afterward. It's like, 1956. This is when my mother was two years old. I mean, this is 55 years ago. And when I grew up, I only hear this as a beautiful melody. That's it. And this piece is very popular as a traditional Chinese song.

Fate/Extella Unveiled: “A Dynasty Warriors Clone!?”
Phantom World Shrinks Substantially
Miho Nishizumi Yukata Figure
Marshmallow Imouto Succubus Suitably Squishy
Shibuya Rin Ero-Cosplay by Tsubomi Totally Scandalous