Quote from that link:
'Its potential strike date is March 21, 2014, but astronomers say that any risk of impact is likely to decrease as further data is gathered'.
Right now there's probably several thousand possible flight paths. That number will narrow as it approaches and as the paths toward the Earth are eliminated, the risk of impact decreases.
Of course there's no guarantee the paths toward the Earth will be eliminated.
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Mark}--->8-8->
If you're not the lead dog, the scenery never changes.