Seeing as it's been in development for this long, I kind of hope they kill it off. Start from scratch immediately thereafter, certainly, but I really wouldn't be surprised if keeping every asset they've already made ended up making the game worse.
Also, a little part of me wants it to be a PC exclusive. This isn't because I am among or a sympathizer of the PC Gaming Master Race (my laptop can't properly play Thief fucking 1).
It's because I can't think of another series that would lose so much in being dumbed down.
And bear in mind that I thoroughly enjoyed Thief 3.
I just can't see it being Thief if it was simplified any more than that, and if it were released multiplatform, it would probably be.