At the moment closed beta players are being asked to finish a tutorial mission -- as either human or cylon -- then are sent off to freely explore the universe. They can experiment with mining, PvE or PvP content, or even exploring the Battlestar, space outposts, planet bases or a Cylon basestar.
Dramatic missions will help to shape the overall storyline of the game. Tactical space combat seems to be the primary focus, but avatars are obviously involved. As the game is officially licensed, it will feature sights, sounds and ships from the series.