http://www.giantbomb.com/quick-look-resident-evil-5-pc/17-1262/ - Gameplay video, shows the controls and everything. Also shows that Brad might actually be a rather stupid individual considers he couldn't figure out how to press C to quick turn, or how to heal Sheva (hint, look at the screen, Brad!).
Some observations:
The default control scheme is similar to type d from the console versions. There's a crosshair in the middle of the screen when aiming, and whenever you move the mouse the entire screen moves. You can turn around ridiculously fast with the mouse. Mouse also works in inventory screen and all the menus.
I paused through when they showed parts of the mouse/keyboard settings screen and noticed a few things:
You can bind the inventory quick-equip to the "d-pad" (probably the direction keys) similar to the console version. Or bind every inventory slot to its own key (default is 1-9).
The left/right movement keys is called "move/turn left" and "move/turn right" so it sounds like you can turn on tank controls for mouse/keyboard if you want.
There's keys you can bind for camera movement. Is that for all camera movements, or the camera you use in type a controls on the console versions? I guess really crazy people might be able to play the game using only the keyboard if they want.
You can quick turn by pressing back and run (similar to the console versions), or you can bind it to its own key (default is C)
Top choice for keyboard/mouse setting is called "control type" and the default is "mouse look" with the text "A traditional control scheme for players used to third-person shooters." What could the other choices be? Maybe Lost Planet-style with a crosshair which moves across the screen? Maybe with a laser sight? Something similar to "type a" controls from the console versions?
There's a key for "quick slash". Probably for doing one single attack with the knife.
You can reload the same way as in the console versions (aim+action button) or bind reload to one specific key.
The controller settings is for gamepads and has exactly the same choices as the console versions. Shows buttons and picture for 360 controller, hopefully it'll support other gamepads too.