WTF: I never played any Thief game in my life. However after excellent Deus Ex HR I'm buying anything from Eidos Montreal team, so of course I preordered months ago.
I never did myself as well but until recently i managed to delve into the beauty that the dark project is. Needles to say it's the best stealth action game i played to this day and it's probably the oldest one and the one that started the genre - loved the missions, the story, the guy that voiced garret captured his character perfectly, loved the gameplay and how you can interact with the environment and freedom of movement (rope arrows, water arrows, moss arrows, ledge muscle ups, surface noises and things like that), loved the dark theme as well.
As for the Thief 4... the voice actor is not the same witch is a major blow. Graphically looks great, gameplay remains to be seen. What will suck is overuse of ingame cutscenes, carbon corridor linearity, press x to jump over, regenerating health and the rest of the modern day bullshit that we call modern but for some reason i think we are going backwards with it...