Kind of vague but there’s still so much that can be speculated about. It looks like a prequel set during Gwyn’s war against the dragons however I still wouldn’t put it past From Software doing a complete revamp, no matter how similar things appear. And if it is indeed a prequel then there’s the matter of just who the characters could be, the apparent hero’s face off with the dragon looks pretty familiar to say the least and we must also consider just why the apparent Lord’s Blades are hunting him.
Either way with so little information out there really isn’t much conclusive that can be said. Hopefully From Software and company will keep the difficulty similar to Dark Souls itself, unrelentingly brutal but still easy if you take the time to sit down and think with enough ways out if you know what you’re doing (upgrading/summoning).