I think that Gox has lost customer funds and Gox is insolvent, but not nearly to the degree that a 750,000 BTC loss would imply. GoxBTC's sold as low as 0.07 BTC = 1 GoxBTC on BitcoinBuilder, and right now the price is 0.14. If a company looking to takeover Gox knows that the solvency situation is not that bad, they could buy up a great deal of GoxBTCs at less than 20% of face value. In fact, maybe that is what is happening now. Perhaps this is all it takes to regain solvency, or perhaps they cut a deal with remaining depositors for 500 mBTC on the coin. With the current FUD in the air, I bet a lot of depositors would jump at a chance to get 50% of their funds back.
If the 750,000 BTC loss is true, I think it is game over for Gox. If the 750,000 BTC loss is true, I also think this was an insider job.