The strength of the bitcoin currency lies on the weakness of the current economic system.
If Greece crashes, if the US crashes, if the world goes to hell, suddenly the value of alternate economic systems will raise.
Even bartering becomes attractive, and it was very evident in the Argentine economic crisis in 2001.

The history of humanity is plagued with examples like this, it is in our human nature.

The difference with these alternative "backup" systems, the bitcoin can become a strong foundation and a currency by itself.
This is something quite unique in the history of humanity, this uniqueness is due to the advancement of technology.

Definitely, it will NOT just stay within the hackers circle.