I preloaded the game last night on steam and played the first level very briefly before heading off to work.
I'm running a 1st Gen Asus G53JW. I can either run the game at 1080P with Tesselation / AA / SSAO / off at around ~20 frames OR run with everything on at 720P and around ~40 - 60 FPS. I can't be more specific as I didn't have time to run a benchmark, or find the settings to show the exact framerate.
Overall the game atmosphere is amazing. A small touch of consolitis on the controls - Crouch is a toggle by default, which I find annoying. Also the chat menu uses a Up, Down, Left, Right Response guide similar to a Mass effect chat wheel except you need to press an Arrow Key (WASD) to select your choice and then confirm it by pressing the 'enter' key. This game was definitely designed for a Controller first. A little clunky, but overall a small nitpick on an otherwise impressive game.