First, let me just say that I fully agree that the properties of the bitcoin system create a floor value that typical private currencies wouldn't have. However, I do think that there are really only two possible explanations for the crash:
1) A short-term speculative bubble has burst. The price has dropped to one based almost entirely on the current usefulness of bitcoins as a medium of exchange and long-term investment vehicle. The price will shoot back up if there's another speculative bubble. Otherwise, it will gradually rise or fall as the value and usefulness of the bitcoin system changes due to adoption, competitors, and so on.
2) Unique events (early adopters selling, stolen bitcoins being dumped, etcetera) have pushed the price way down. If not for these, the previous increases (whether due to speculation, the usefulness of the bitcoin system, or whatever) would have continued, and as soon as this stops, the price of bitcoin will begin sharply increasing until the next such unique events.
Most likely, the truth is between these two.
Or, in summary, once this unique event ends, the price of bitcoins will go up, go down, or stay about the same.
Or,
3) an on-going world-wide credit contraction that will dwarf the events of 2008 is compelling btc holders to liquidate into the one asset class that is rapidly shrinking: USD.
Although it would be helpful for gold to drop to give credence to that theory.