Hi!
If you play at lower than native resolutions on a HDtv, monitor or your notebooks screen try to set your screen resolution to match the chosen resolution ingame. This may lift the blurriness of the background, sharpens the image a little bit and you may get a little better performance (specially on slower machines).
If you play the game on a HDtvs screen on lower than native resolutions (in my case 1366x768p on a native 1920x1080p FullHD tv with a good quality HDMI cable), try to set the tvs sharpness setting to its highest. In my case it helped a lot with image clarity.
Also I read somewhere in the forums that if you set your msaa to 0 (tipe in the command line the following: msaa 0 and hit the enter button)
it may reduce blurriness and sharpens the background image, but in my case it did nothing.
And a little tip for Nvidia (I play on a laptop with Geforce GT630m on Windows 7 64bit) users: I was able to disable msaa completly from my nvidia control panel so I don't have to retype the above command on area transitions.
I hope it helps to some of you.
PS.: Sorry for my english its not my native language.