As of patch version 1.51, you have the ability to respec Realm Abilities.
You may accomplish this by standing in front of your class trainer and typing /respec realm. Keep in mind that after you have done this, nothing changes on the existing training window. You will need to click on your trainer again, and then you will be able to redistribute your points as you see fit.
You only get 2 respecs per character.
Additional information about Realm Abilities can be found at the following locations: [Realm Abilities]
[Realm Skill Point Clarification]