I have more $ in Mt.Gox than BTC. (My acct is negative in BTC.) If everyone is like me, then there is more pent-up cash than bitcoin in Gox. Who knows what the ratio is on the whole? You presume everyone has bitcoins there, but not dollars. Any argument for that presumption?
In fact, as reported by several people on the forums (if I remember right) and on IRC, just prior to the hackcrash people were just starting to get funds cleared into Dwolla and then to MtGox. I doubt everybody spent all their cash prior to the crash and I'm guessing there's quite a lot of USD stuck in MtGox right now. That, in itself, might explain the flat exchange rate over the past few days (i.e. the people with the money can't use it right now). Add to that the fact that the whole event has got people a little on edge.
