Hopefully they'll reset it, cause I cant play it untill wednesday. And I will be playing campaign
The leaderboards will be reset the day before the launch to make sure there are no unfair advantages for the pirates.
The Xbox 360 is trying very hard to kick the PC from it's throne as most pirated platform. The game was pirated and released on the Internet a couple of days back and many (MANY) players have already been playing Modern Warfare 2 almost two weeks before it's official release. A quick search for Modern Warfare 2 on Youtube will give you tons of videos of gameplay, but watch it as some contain massive spoilers.
Now that all those players already got a head start on the rest of us, still waiting for the game to be released, Infintiy Ward will reset all leaderboards to make things fair again: