http://blog.zorinaq.com/?e=55 says "...Contrary to previous claims from the MtGox owner, this indicates that many accounts had been compromised for at least days, if not weeks, before today's attack. This may explain some of the reports of Bitcoins being stolen from MtGox accounts in the previous days and weeks, as reported on the forums."
Something doesn't add up. My password on the posted .csv was created on the evening of June 16 west coast time. If blog.zorinaq.com is correct, then there were at least two separate seizures or losses of user lists from Gox, the first being long before Friday's release.
Looks very much like there was some kind of ongoing compromise that caused the password list to be leaked on more than one occasion over a period of at least two days, yes. Probably more than that if we assume the attacker attempted to brute-force the passwords themselves before posting on that forum or offering them for sale.