Well in my personal Opinion every predicted disaster has always turned out to be nothing more than a mole hill. The only truly devastating occurences are the ones we didn't know were coming.

and a Polar reversal wouldn't do much to our way of life, I think the only thing i'm worrying about is all the magnets reversing their poles too. Which will screw over many of our fridges! All the magnets will invert suddenly.

But seriously, if this was a big threat to human life, it would have been plastered across the news, telling us the required information to get ready for a disaster of this magnitude.
And the whole mountain thing, couldn't possibly happen. If i got a pebble and stuck a magnet on either side of the pebble, then suddenly inverted the polarity, the pebble wouldn't shred thats for sure.