Nash Equilibrium.
Agreed. At least, as it pertains to normal market participants. I believe a whale can break us out of this equilibrium (more at end of post).
Current, relatively-stable prices are:
Mt Gox - 106.25
Other BTC-E/Bitstamp - 97.50
Price difference of 8.75.
8.75 / 106.25 = 8.25%
At equilibrium, people seem willing to take an 8.25% loss on their funds to have them represented somewhere other than Gox.
I take that to mean that, absent conclusive data, the market speculates there is an 8.25% chance that Gox defaults, or that they will fail to be able to receive their fiat.
(Or viewed from the other perspective, people are willing to assume the additional risk of getting nothing, in exchange for an 8.25% premium when they sell.)
I am expecting this stasis to be broken when a whale decides to leverage the power of his money by driving the price on a non-Gox exchange above the Gox exchange.
A market buy alongside a new support wall, let's say driving the Bitstamp price up to 110 while Gox is at 106.25.
What happens next?
Suddenly, everyone sitting at Gox not wanting to take a hit by re-buying, now has a motivation to buy their coins, as they can now move them over to Bitstamp.
Except this in turn moves the price on Gox back to equilibrium (or more likely, a premium over that, as we are now.)
Which suggests we are no better off than when we began.
Except we're not.
The market as a whole would now be xx users/volume closer to being done with Mt. Gox.
The whale will have won, as he bought coins from 95 to 110, and the resultant price jumps on Gox establish a new floor of 110 for all of those coins.
After the necessary several days of consolidation, he or another will try the same thing again. Each will move price upwards.
At some point, the trick stops working, for one of two different reasons:
1. Not enough volume and users remain on Gox - the well is completely dry, the market just needs to realize it. (This will happen relatively quickly, as volume is easily discoverable data.)
2. The repeated price moves that were profitable for one in fact begins a true rally, one which is not focused on Mt. Gox, but rather,
any other exchange.