If there is a third game, I do hope that they stay true to the first one a bit more.
What I'd like to see carried over from DS2 is the Armor system, just weapons should stay like DS1.
Well since the Remaster of DS2 is made by mostly Vigil Studios members who worked on previeous titles, I wouldn't doubt that a DS3 gets good.
That would be the death (no pun intended) of the franchise to me. Joe Mads artstyle was what has drawn a lot of people towards the game and is what (in my opinion) makes it a) stand out on the market and b) let's it age way better. I can look at DS1 and still think it's beautiful, while most games that go the more "realistic" route quite aged after a year or two.
Keep in mind, it's only my opinion.