The next expansion of World of Warcraft will have a lot of changes to the current game and player versus player (PvP) is no exception.
One of the biggest change to World of Warcraft’s PvP system is the introduction of the PvP point system. Currently to get high end PvP items you need honor points, arena points and a high personal arena rating. The new system in Cataclysm will introduce Conquest points which is explained here:
* Honor Points — Low-tier, easier-to-get PVP points. There will be a maximum cap to how many you can own, but no cap to how quickly you can earn them. Earned from most PvP activities.
* Conquest Points — High-tier, harder-to-get PvP points. There will be a maximum cap to how many you can own, and a cap to how many you can earn per week. Earned from winning Rated Battlegrounds or Arenas. (currently called Arena Points)
In other words the current Arena points will now be known as Conquest points and there will now be two ways to receive these points: Arena and Rated Battlegrounds.
Another big change to the PvP system will be the remove of almost all personal rating requirements on PvP items. The reasoning behind this is because Blizzard believed that rating requirements was a rich-get-richer syndrome.
More info on these changes can be found here.