Dexterity is being split into two new ability scores: Agility and Coordination. Agility will primarily represent a person's reflexes and speed (how fast can you react and move?) while coordination measures a person's ability to control their movements with precision (including both ranged and melee combat as well as fine motor-skills, such as crafting jewelry). Coordination may also play a role in coordinating attacks from a strategic level when more advanced professions are released.
For a more detailed look on Agility and Coordination, see our official game library:
http://www.eaxia.com/library/as/