Bloodborne is still one of this year's best games by quite some way I'd say. It was probably the first big budget game to really knock it out the park in 2015 at the very least. That's why I'd be excited to play more if DLC was announced to be in the works.
That looks like it's going to be happening too. According to PlayStation boss, Shuhei Yoshida, an "expansion" will be coming at some point. He took to Twitter saying:
So I have been asked by many people if we are making DLC for Bloodborne. I can say… An expansion is coming. More info later this year. :D
— Shuhei Yoshida (@yosp) May 21, 2015
From Software have a really good track record when it comes to DLC, so hopefully this will end up being worthwhile. It would be cool to get an announcement at E3, but I have a feeling we have a longer wait than even that for more information.