The new raid lockout changes for Taiwan and Korea adjust the lockout timers for the patch 4.0 and 4.2 raids. The lockout timers for these raids will now reset twice weekly instead of once. These raid lockout changes are being made to allow players to raid more often and get more chances at epic loot drops. Players will be able to down current Cataclysm raid bosses twice a week, accelerating players' progression.
We are testing these new raid lockout changes in Taiwan and Korea first. Our goal is to expand this change to other regions in the future, but we don't have anything further to announce at this time with regard to North American implementation.