My money is on the Caldera volcano in Yellowstone being The apocalypse... But Asteroids arn't a half-bad substitute.
As for the nukes, In all seriousness Nukes are unlikely to solve much. If the asteroid has an orbital period of 324 (according to the article) and crosses our orbed, then it must be in a relatively elliptical orbit with earth near it's apoapsis. If that is the case, then simply blasting it with a Nuke anytime it gets near earth will effect very little change in it's orbit, and even if you do blow it into little kibbles, those kibbles will stay on the exact same course.
If this really IS a threat (not saying it is or is not), then the best way to deal with this is to send a craft out to intercept the Asteroid near it's apoapsis, and apply thrust AT the apoapsis to change the orbital period. Unfortunately The launch window for such a mission would be very very small, and might only come around once or twice before the supposed 30 year impact timeframe, and depending on the mass of the asteroid, we still might not be able to effect enough of a change in orbit...
Anyway, My 2 cents.
"Well, if I am not drunk, I am mad, but I trust I can behave like a gentleman in either
condition."... G. K. Chesterton
“questions are a burden to others; answers a prison for oneself”