According to
RT.com News, NASA is considering options to divert a 60 meter asteroid 2012 DA14. It expected to pass by the earth closer than geosynchronous satellites during February, 2013. The asteroid was discovered by Spanish stargazers in February of 2012.
Options to change the path of the asteroid are limited as it would take more than a year to launch a mission to destroy or divert it. One of the options being considered is to paint the asteroid to change its course. This may keep it clear of the earth this time but would make predicting its path more difficult in the future.
Updated report: Mike Wall from Space.com: NASA researchers report (March 6, 2013) that the small asteroid will not get closer than 3.2 of earth radii or 20,400 kilometers
If an asteroid of this sizewere to impact the earth the damage is expected to be similar to the 1908
Tunguska blast in Siberia which leveled more than 2000 square kilometers of trees. This is a
link to the Russian site on the subject. A Google translator is available to convert most of the text into English.
Scientists are not certain of the precise cause of the Tunguska event. The most likely theory involves an icy portion of a comet that exploded in the atmosphere above the area. A volcanic eruption or a meteor have also been considered.