The current drop certainly has a panic sell feel to it. If this were simply due to oversupply, I'd expect a continuing gradual decline similar to what we were seeing from ~$15/BTC to ~$12/BTC. This doesn't seem to be a typical mass sell-off, though. It's more like an individual or small group of sellers with a lot of capital to dump on the markets, possibly using algorithm trading. Too much rapid probing action for me to think otherwise.
With the recent issues at MyBitcoin, I have to say that I am suspicious. However, proving this isn't my priority, nor would it matter as the damage has already been done; a waterfall was triggered. As long as the exchange remains above the $5-6/BTC level, mining remains profitable in major currencies and I wouldn't be too concerned about these growing pains. I think it is unlikely that Bitcoin will go to zero - it requires actual work to produce and cannot realistically be destroyed, much like gold. In fact, I find that BTC/NMC are very similar to gold/silver, respectively.
From loose personal observation, the Bitcoin exchange rate seems to presage major equity markets, which isn't too surprising. I imagine there are a good number of savvy financial-types taking part in this, easily capable of sophisticated technical analysis. Dabbling in the Bitcoin markets could be a form of front-running established ones.
As for the whipsaw action today, limitations of information available on overall holdings (market cap) and volume, in addition to dark pools, make it very difficult to gauge where the demand/supply will settle. Sure, lines on charts can help but they don't tell the whole story. There isn't really enough of a pattern history to determine reasonable swing ranges either. Of course, as the markets mature, these patterns will become more clear.
My view mirrors what has been suggested by others - the Bitcoin environment absolutely requires universal accessibility without needing highly technical skill, and a level of security that overcomes concerns about hacking and unscrupulous custodial services. Ideally, this would include a means of utilizing mobile devices to run the client and periodic backup of the wallet to an encrypted online location; the wallet encryption using either strong password encouragement of at least 12 characters or separate storage of the key.
Cryptography isn't my specialty, although the principle seems straightforward enough. With
this ruling on identity theft, it is becoming apparent that people will need to keep their online personas and digital information much more secure than in the past. The overall cultural mood is certainly shifting toward that, so acceptance and understanding of encrypted Bitcoin wallets should be a minor hurdle.
Automation is the key. If I can install a Bitcoin client app on my Android or iPhone with the ability to make transactions (QR codes would work perfectly), check my balance and seamlessly backup/restore (even to Dropbox as long as the wallet is heavily encrypted before upload), then it's ready for prime-time. I'd even pay a few USD for the privilege - not everything Bitcoin related has to be paid for with Bitcoins until the system is mature enough to stand on its own.
To sum: hold onto your BTCs and mind the speed bump.