Infinity Wards Robert Bowling announced today that a patch will be coming on March 8th that basically the addresses the issue of hacking on Modern Warfare 2.
Since the PS3 jailbreak has become very common to everyone, quite a number of PS3 users were hacking their way through the leaderboards and the rankings of Modern Warfare 2.
Finally, those issues will be finally be addressed starting March 8th as Bowling confirmed that a patch is coming. As for the other platforms, the patch is still in pending and should be coming out shortly.
Just received word that we expect the latest Modern Warfare 2 patch for Playstation 3 to be available March 8th worldwide. Addresses hacking Robert Bowling
source: Just Push Start