WoW senior game designer Greg Street has detailed the game's upcoming dual talent system in a Q&A over on the MMO's official site.
Only two specs will be available at launch and will allow players to switch between customizations easier. One can be for healing and the other damage, or if you prefer, one for raiding and one for PvP.
To apply these specs to your character, you will have to visit your NPC class trainer and pay a one-time fee -- after which you can switch between them for free at any Lexicon of Power.
The update's expected in the next patch.
The option will only be available for level 80s at first, as Blizzard didn't want lower levels to get bogged down with the "extra complexity" of the changes while still learning the game. However, Street did point out that if the feature proves to be popular, they may consider expanding it to everyone.
Loads more information can be found through the link.