It's a very sobering thought that we'll inevitably be less lucky, although the likelihood is that it'd hit the sea or an uninhabited/ low population area.
I remember, in 97 or 98, an asteroid being spotted that initially appeared likely to hit around now. It was much bigger than the one you mention and could have been a doomsday event. Further calculation quickly ruled out a collision, but for a short while scientific bums were squeaking.
Ian Rankin wrote a piece for The Scotsman about what life would be like if the original projection had been right and humanity had 20 years to ponder its annihilation. Needless to say, society fell apart. It is ironic that if we did get a lengthy warning period we might pretty much wipe ourselves out in anarchy before the stone hits us!