From CNN: Asteroid passes close to Earth
Here's the quote I found scary: "If discovered in advance and with enough lead time, there is the possibility of pushing it off course, if you have decades of advance warning," McNaught said. "If you have only a few days, you can evacuate the area of impact, but there's not a great deal [else] you can do."
Armageddon with Bruce Willis and Ben Affleck is one of my favorite movies. It's super dramatic, with a good balance of action and humor. But I don't know if NASA currently has astronauts trained to pull off that kind of stunt with a week's notice.
In fact, I don't think there is any kind of real life asteroid defense plan other than duck and cover. (Think about the other more boring doomsday asteroid movie, Deep Impact) With the millions of asteroids flying around space, it's a miracle a big one hasn't smashed into our planet yet.
My plan: Build a base on the moon and equip it with a giant laser (Austin Powers 2). Then search the earth for young men and women who display exceptional skill playing the Missile Command video game and have them defend the planet (The Last Starfighter). So when I become President, don't be surprised when I order video game tournaments for the sake of national security.