Masaaki Yamagiwa has provided more information on Bloodborne over at PS Blog.
Bloodborne takes place in an ancient, forgotten city called Yharnam, known for an old medical remedy. Over the years, many hopeless and afflicted people have made long pilgrimages to Yharnam in search of help. As the main character, you are one of these travelers. However, you find that Yharnam is also cursed with a horrible endemic illness. You must navigate the perilous streets of this city, fighting off nightmarish creatures, malformed beasts and deranged mobs stricken with this horrific illness. Face your fears as you discover the secrets and mysteries of this dark and horrific world where danger, death and madness lurk around every corner.
In Bloodborne, the combat is based on intense life-threatening battles. One of the ways we are bringing that sense of danger to life is by keeping the deep strategic elements from Demon's Souls, while also transitioning from the passive and block-and-attack style of Demon's Souls to a quicker, more offensive and active combat style with close-range weapons and guns.
From the beautiful and melancholic architecture to the debris lining the street, Bloodborne will deliver an extremely rich and detailed world, all thanks to the power of the PlayStation 4 system. In addition, the PS4 system has allowed us to have an expanded draw distance, so we can show more of the world at any one time. New lighting effects allow us to add more atmosphere and tension to the game, making the horrifyingly detailed beasts and giant boss enemies you'll be facing even more frightening.
I hope to be able to share more about our online features later this year, but I can say that we are developing new kinds of online experiences that allow users to share their adventures. We also look forward to giving fans new ways of playing and sharing thanks via the PS4 system's Share capabilities.
Special message from Director Hidetaka Miyazaki:"Creating Bloodborne as a completely new game on the new PlayStation 4 hardware has allowed us to really push the envelope in myriad ways. That being said, in more ways than one, it also very much retains our distinct, signature style. As has been at the core of our development philosophy since Demon's Souls, we make true games for people who love games. Please watch for more to come on Bloodborne, and thank you very much for your support."