I posted this topic after reading this article:

http://www.hightechforum.org/bitcoins-a-crypto-geek-ponzi-scheme/

It concludes with the question "Can Bitcoin Survive After the Bubble Bursts?"

I was looking for some reasons on why there's more to Bitcoin than merely some speculative bubble that might someday burst; what is the intrinsic value within the Bitcoin currency that will stop it going to zero?

Personally, I think the sheer time and energy focussed on and invested in Bitcoin in mining and trading produces that intrinsic value, which forms a valid base for its value as a medium of exchange.