What are you playing it on, runs perfectly smooth on my rig and all my mates pc's.
Edit: apparently there was a patch before the game launched that caused some issues with the fov but I'm sure that'll be sorted, just hold on dude, from the little I've played so far I know the game is gonna be epic!!
Edit 2: Some fixes while you wait for a patch.
Make sure your system has up to date Windows and drivers
Try to increase/Decrease Resolution, it’s a trick sometimes work
Turn off V-Sync
Reduce the View Distance to half, it will make no much difference in visuals but FPS will be great
Set the Textures and Shadowmaps to Medium
Reduce FOV
If you are an AMD/ATI graphic card user, you must kill AMD Gaming Evolved Application before launch the game.
Try turning on Triple Buffering in the NVidia Control Panel.
I can't help but feel its driver related and not the actual game, I haven't had any real issues at all...I've only played about 15min though..lol