Do you know how much, quantitatively, a dump like we saw with Mt Gox (~35,000btc) would impact the market? I believe it's not a straight 1:1 impact on market cap when a massive buy or sell order rolls in, right?

Also, we can monitor the status of Mt Gox wallets here:
http://gaelb.alwaysdata.net/MTgox_watch_CW/index.html
You can subscribe to be notified whenever coins are moved in/out from them.

Keep up the great work!