A new reddit post leaked some details of the upcoming closed-alpha testing of Bloodborne.There will be a testing just before the game’s official launch it is still unknown what features the testers can have access to but this leak might give us the information about it.The source that leaked the original ‘Project Beast’ have leaked this information so it might be true.
Online Multiplayer:

Players will have a choice to make early on in the game, their decision will affect multiplayer

Decision to infect blood with two different strains of the sickness. There are rewards for choices, but also downsides.

Miyazaki-San wants players to feel the fear of having a disease that could consume them, and take their life. This is a ‘hardcore’ mode for NG like a ‘permadeath’. Players must collect blood for their Heart. If they loose Heart strength for too long, the sickness consumes them.
Players must collect Blood Vials and Blood Packs to transfuse their heart health at their Shrine.
The sickness transforms dead hunters into their worst fear.
In NG, you may become a boss later in the game if you collect enough blood to strengthen you heart
You can summon friends via PS4 friendslist

You can no longer use consumable item for healing if you summon friendlier for a boss battle.
Convenient System:

In some covenant, the sickness is very strong and player can choose to ‘consume’ his own heart. This is a permanent choice and binds a character to the covenant permanently. You become a beast, and new controls and attacks open up. Dead hunters will bind to the world when they die, their bodies becoming a regular ‘mini beast’ boss enemy within the world like Red Phantom from dark souls.

Covenant system is not finalized, but some detail I remember. There will be ‘huge beasts’ in the game. If you defeat them you have a choice to become a host for their strain of the sickness at your Shrine. You must invade other player worlds to collect blood for your beast.

In NG, The Beast’s heart will get stronger from blood and other players will have to fight much harder to kill it. One beast is a giant spider, another is a giant snake.

Bloodborne Alpha:

ALPHA will be a co-op boss battle, and some simple PVP invasion covenant testing.
Blood Borne is a PlayStation 4 exclusive which is scheduled to release on Febuary 5 2015.
Not to forget it is from the same director Hidetaka Miyazaki, who made Dark souls 1 and Dark souls 2 so don’t think this game will be easy.