I've been playing Dishonored 2 this past week, and... I am really enjoying it.
For one thing, Arkane has changed the visual look somewhat. The original was pretty highly stylized. D2 is somewhere in between that and a realistic look -- it still has the unique look of the Dishonored world, but rendering it in a slightly more realistic way doesn't pull me out of immersion as D1 did. It's a very nice change.
Gameplay-wise, this is the closest thing I've played in years to another Thief game. (That is meant to be extremely high praise.) I'm playing in a non-lethal/ghost mode, and the old Thief pattern of waiting for guards to be in just the right position, stealthily running up behind them and knocking them out, then hiding the bodies as quickly as possible... Dishonored 2 absolutely scratches that Thief itch in a way that nothing else has for a long time.
It probably does not hurt that Stephen Russell -- Garrett in the original Thief games -- is one of the voices in Dishonored 2.
In this sequel, Arkane addressed the one serious complaint I had about the original Dishonored, which was that most of the skill and gear enhancements were specific to a high-chaos playstyle. You could still succeed with the few enhancements supporting low-chaos play; I just wished I could have had as much fun as the high-chaos players in tweaking my enhancement choices.
Well, that's been sorted.
There are a metric buttload of enhancements in D2, including plenty of powers, bonecharms, and gear upgrades for all interests.
I'm pretty close to the ending of my first playthrough (no spoilers, please!), and this has been some of the best gaming money I've spent in a long time. If there's anyone who enjoyed the Thief games, or who thinks playing a "first-person sneaker" game sounds like fun, I can recommend Dishonored 2 with great enthusiasm.