Between now and the launch of PlanetSide Arena in March, Daybreak has plans for several closed beta events. Players can get involved in closed beta testing either by preordering the game ($20 or $40 packages) or by signing up and being selected. The first event will take place on January 30th, with another planned for February 1st. According to the new FAQ, other events will be scheduled after February 1st and prior to the Founders Season that starts on February 20th.
Those who preorder the game after the first beta event will still be able to join all subsequent events.
You can check out the FAQ on the PlanetSide Arena site.