MtGox's new signup rate has grown significantly in the past month. It went from hundreds to thousands to over 20,000 new traders yesterday. A crash coincides with high volume (1 hour+ trading lag) -- a perfectly technical reason to fix the issues now regardless of the finances. At some point they need to get the new infrastructure in place (see: http://coinlab.com).

I just transferred all my BitCoins to https://btc-e.com - for whatever reason, you are only allowed to withdraw 100 Bitcoins/24 hours. Probably a fraud insurance element - MtGox will cover any fraud, and they are limiting their losses to 100 Bitcoins at a time.

You can withdraw up to 1000/day once your account gets verified, and up to 10k/day once it's "trusted".

At least in case of USD limits, it's about anti-money laundering. The government requires them to keep track of who's doing the withdrawals.

Aside from this, the limit was 400, but they lowered it to 200, and then to 100 when there were issues a year ago (a similar situation to today's - a crash, and people panicking, etc.)

I think the volume/unit time during the crash is generally higher than during the bubble phase. This can be seen in the steeper slope of price-time graph during declining phase compared to the rising phase of most bubbles. I guess fear is a quicker call to action than greed in financial markets.