The open beta has taken a step forward today (Or maybe it was yesterday? Being sick messes with your days.) When the game was first opened to the general public, the 'free' users were unable to play with the larger part of the characters.
As was revealed on their twitter feed, Stunlock Studios, developer of the game, was using this as an opportunity to test the system that would handle rotation of available Bloodlines. However, when the game is officially released, it will return to the previous state, in regards to Bloodlines with a major improvement.
As it has been since the open beta started; the store is closed until release but players are still able to earn Blood Coins, in-game currency, by playing the game normally. Once the game is released, the store will open and you'll be able to spend these coins on currently locked Bloodlines, as well as costumes and weapons for them.
These have no real effect on how the game plays. Each of the options are purely cosmetic changes, and only there for your enjoyment.