Bought this a few weeks ago, and started playing it with the keyboard. Really enjoyed it so far. Have to say I really like the Focus ST starter car, handles so nicely. (no reflection on my current car choice! lol).
Turned on the eyefinity for more peripheral vision, and hooked up a wheel and pedals I pulled out of the garage, and this is the first time I have genuinely enjoyed the wheel'd experience. Using an old Microsoft sidewinder precision or something like that (no feedback, just resistance) and it is just so darned accurate and you can set the dead zone to zero.
Just played a fast/short 4 laps in a city (no idea where) and I actually got an adrenaline hit from it. I can't ever remember getting that in a racing game before.
I have another wheel here (Logitech Driving Force (for Xbox 360), that should work on the PC, so will give that a go when the breakaway to usb cable turns up.