Do people who complain about letterboxing hate their TV bezels, too? Are they mad the game doesn't project on to the surrounding walls? What about blinking, how dare a game waste the space on the inside of your eyelids!?!
The "filmic" part of is it not because of the black bars... it's because of the aspect ratio that gives a more expansive horizontal view. It makes for interesting shots in cinematography.
I'm going to say I didn't mind it too much in Dragon's Dogma, but that game really did it due to hardware limitations--none of their cutscenes were particularly well "shot" in terms of cinematography, I think. And, I'm not sure if it'll even work well in gaming where the player (usually) has control of the camera in gameplay. That'll just throw the whole point out the window. Cutscenes make sense, but they're not actually for "playing" the game.
Why is this such an issue when everyone here knows the game will look fantastic? If the devs are looking for a more cinematic experience, then I say go for it. It's something different for the gaming media and a welcome change.