From the publisher:
Some races are too powerful for heroic tier play; they are stronger than the normal races, or have more exotic powers. However, using the rules set out here, these races can be included in your paragon or epic campaign without unbalancing it.
A paragon race character does not choose a paragon path; they instead gain some racial features in place of paragon path features. As they progress through the paragon tier, their racial abilities become more prominent, similar to a character progressing though a racial paragon path. They choose an epic destiny as normal. Furthermore, a paragon race character does not gain the ability score increases that most characters gain at levels 4, 8 and 11.