I like this thread. A lot. Thanks, @Ecstasy.
Let me add one more review-ish video of the PC version (take care, might be spoiler-ish):
There's also a great Errant Signal video about Dishonored, which pinpoints the game's weaknesses and offers some deeper thoughts, but that's gonna choke you with spoilers, so look it up on your own, if interested.
Anyway, the game runs and looks absolutely great on PC. There are lots of options to make it run as nicely as possible on your machine, and of course you can use a gamepad if you want to.
I haven't played all that much myself, currently in chapter 3 or so, but what I played so far was fantastic and offered a thick atmosphere. Unlike most other Bethesda-published games, Dishonored was fairly bug-free for me so far - Arkane Studios did a fantastic job there!
However, the game MIGHT be rather short. It offers a lot of ways to beat the missions, and encourages replayability and different playstyles (if you run through the game killing everything you'll get high Chaos ratings, which will lead to a different ending, for example), and there's plenty of stuff to explore in the world. BUT if you don't take your time and find your own pace, you might finish the game in under 10 hours, while other players might take 20+ just for their first playthrough.
Fantastic game, might have used some more character depth (shown as opposed to told depth, at least), but gameplay-wise it feels very much like a modern Thief game - if you desire playing like that, at least.