They also announced that PlayStation Plus members will also be gaining access tomorrow as well. The beta does not implement the full interaction between the two games, but two crucial aspects will be included: orbital strikes, and cross-game chat.
The orbital strike mechanic is really the tool that will make or break the interaction between these two games. For the purposes of the beta, players will be able to call-in strikes from a war barge orbiting the planet. When the full game goes live, players within EVE will take the place of the war barge, supplying orbital strikes for teams on the ground in Dust 514. Which strikes are available will depend on what turrets and cannons players have outfitted their ships with.
CCP has also said that they have enabled keyboard and mouse support on the PS3 version allow PS3 players to choose how they'd like to play.
Dust 514 made some big strides in gameplay this year at E3, and we're going to be very excited to see how it pans out when it finally releases sometime later this year.