Dual specs will allow a player to have two different specs ready for immediate use without having to head back to a capital city to respec. You will be able to switch between two pre-defined talent builds (and associated glyphs and button configurations) anywhere in the world, so long as you're out of combat. (If you want to change one of these build after you've initially set it up, you'll still pay a standard respec fee.)The feature will allow players unprecedented opportunities to play various aspects of their character at their choosing.

Dual specs also represents one of the most important updates to the game since launch.  Healers will be able to have a viable farming specs, and PvPers will easily be able to switch into a spec that is efficient in PvE.

This feature is being introduced with patch 3.1, and is currently being tested on the PTR.  Collected below is the latest information WoW Insider has on the dual spec system.

Basic Information

• Dual specs to cost 1000g
• Dual specs available at level 40
• Dual speccing in three easy steps

Latest News

• Encrypted Text: Rogue videos from the Patch 3.1 PTR
• Ghostcrawler: Dual specs will not change design decisions
• Patch 3.1 Dual Spec walkthrough gallery
• Dual specs available at level 40, reagent requirement removed

General Dual Spec Information

• Ghostcrawler’s Implementation FAQ
• Dual specs and loot
• Dual specs and saving gold
• Dual specs at low levels
• Dual specs will not change design decisions
• Player reaction to dual specs
• Dual spec updates: November 13th, November 26th, December 8th February 5th
• General dual spec discussion
• Who will dual specs benefit the most?
• Will dual specs affect your healing squad?
• Will dual specs eliminate the tank and healer shortage?

Dual Spec Advice for Each Class

• Death Knight
• Druid
• Hunter
• Mage
• Paladin
• Priest
• Rogue
• Shaman
• Warlock
• Warrior