it's also not clear yet that the 250K BTC on mtgox were actually "real". plausible (likely?) that they were created out of whole cloth in the mtgox database by the attackers (UPDATE account_table SET btc_balance=500000 WHERE USER_ID=schmucko)
if this were the case then this attack would have fooled the mt gox software into sending bitcoins from the mt gox wallet right? Essentially stealing the bit coins from mt gox, not other users?