This is really a question that has been stuck with me over the past few months (since I joined the forums basically) and I really can't answer that. You can ask this question at the beginning when we first heard news about it and you can ask it now and the answers would be vastly different.
Like I mentioned before I liked to envision what the final product could be when I first heard of Dishonored and some really amazing things came to mind. Now that I have read and seen a ton about the game however things have changed. I have a more directed view of what is to come in the next two months. I have more solid expectations and fears on what Dishonored will be. So let me contribute to this thread:
I want Dishonored to tell a great story with twists and great characters and how they develop. The plot is already good and most probably well paced and structured. I want to see the characters, I want to have moments of introspection when I play a game. Let's hope Dishonored is one of them.
I want the game to handle a lot of tough themes. Losing a loved one and being helpless to stop him/her from being taken away from you. And not just those, the plague, the corruption, the dystopian world. Those are things that can give birth to a great story with great meaning.
I want balance, challenge and a solid gameplay. The game probably has those already but there is always room for failure and let's hope it doesn't fail.
The endings. Now this one is kinda pointless because I never judge something by its end but rather by the journey and experience it gave me. I really really want them to make endings that show what all this, all your struggles amounted to. What your anger or compassion drove you to do.
I want the game to have a great impact. This would basically amount everything I've said but I actually did have a dream that a week after its release, Dishonored was considered the biggest title in gaming history. Imagine if that is the case. Imagine the people like me who think Deus Ex is the best game ever start saying Dishonored is the best game ever made. That would be beyond amazing. That is probably not going to happen but I can still dream, they are still free after all.
So guys what do you think? What would make the game great?