It appears that whatever Sony did to mitigate security issues in its most recent PlayStation 3 patch has enabled Infinity Ward to address its "unplayable" version of Modern Warfare 2. Creative strategist Robert Bowling announced on Twitter that a patch "will release on PlayStation 3 worldwide on March 8," with an Xbox 360 and PC release following at some point. The patch, Bowling said, is specifically intended "to address hacking."
Bowling detailed the process on the Infinty Ward forums, having updated his original post about the PS3 situation as new information was available from IW while staying intentionally light on details, "as we don't want to give out any information that could potentially hinder the security any further." He additionally noted that the patch "will also address a small geo exploit on the map Fuel, which players exploited in order to get inside a rock on the outskirts of the map." Apparently some players were ... rocking that exploit real hard.