StingingVelvet: If you set the game to a 16:9 resolution and then have your GPU or monitor scale without fixed aspect ratio then yes, it will stretch and fill your screen. I find it hard to believe you did that without knowing what was going on though, or that you did not notice the horrible quality effects of stretching an image and running an image in a non-native resolution on an LCD.
In any case, who cares? The game has never used a 16:10 aspect ratio and that's all that matters.
Trust me, I would have noticed the black bars when I first launched the game, I would have tried to fix it, I would have found that TW2 doesn't support 16:10 and I would have pondered that ridiculous fact. The stretching was obviously not that bad then, but GPU scaling is off and was always off. Now, what did they change to fuck up their pseudo 16:10...