Both PS3 and PS4
Sony and Bungie seem to have a lot of deals going on. While everyone is quick to judge Microsoft as the king of exclusivity, Sony has worked out exclusive content, an exclusive alpha, and now, apparently the game will be exclusive in general to the PS3 and PS4 in Japan.
That's a whole lot of eggs in one basket, but if you played the alpha last week you can see the appeal. I bet Bungie is already gearing up for a Destiny 2 and 3.