In the long run a $60 bitcoin might not be a bubble at all.  More and more businesses might accept it, drug money might be poured into.  Money from hedge funds might drive up the price just like investment firms are driving up housing prices in place hit hard by the real estate bubble.

However a glitch here, a bug there and a virus there can send prices tumbling. 

Perhaps a bit coin might be priced where gold is in the near future.