Speaking to OXM in a recent interview, Stephane D’Astous of Eidos Montreal shared the team's vision for the fourth game: "There are a lot of challenges to bringing back a great cult IP, but we consider it like a new IP and we are going to respect the spirit of the franchise like we did with Deus Ex."
D’Astous went on to express the importance of refreshing the franchise, claiming that this new Thief title will "bring more than just stealth" to the experience. “Deus Ex was the kick-start of this new series of great games, and Thief will be part of that. We don’t want to deliver the same each time. Our mandate is to bring new stuff to the table; games that we’ll be talking about for years.”
I can't say I have much experience with the series myself, but after witnessing what an awesome job they did with Deus Ex: Human Revolution, they've definitely got me interested. If you'd like to second my sentiments or disagree with every part of your being, feel free to spill your thoughts in the comments below.