Spurred on from disagreeing entirely with "Hardly a surprise, but it suggests something open-worldy to me, rather than a series of missions. That ’s what we want."; what do you want from Thief 4?
Personally, I'd prefer a return to individual missions - but I'd like a storyline with branching missions and multiple ways to end up at the end of the game(and a few different ways of ending it).
I was disappointed with Thief 3's 'hubs', and found the missions overall lacked a lot of the scope and subtlety of the previous games.
I'd like Garret back, but I'm not averse to it trying something new. I think I'd also like more focus on being a thief, and less on the storyline and defeating an ancient evil.... at least until towards the end of the game.
Aside from that, I'm easy and would just like the level designers to go to town and show us what they've got.