I have a contour and my friend has a hero 2. here's the breakdown
Coutour is easier to use by far, no more "is it on? is it on?" one beep on two beeps off (that might be backwards) for both power and recording. The settings and mounts are harder to use though (a big part of that is my use of a google mount).
GoPro is water-proof but Contour is water resistant which is plenty for snow.
The contour is built very solidly (i'd say more than the GoPro but the case probably makes the GoPro more durable) the footage is very similar but I really hate the contours exposure settings(i have the Contour HD 1080p not one of the more recent models so I can't comment on them)
The flat mount on both sucks because it's flat and helmets aren't. I intentionally dented my helment to ensure a better fit, my friend just stuck his on there and it has stayed sofar.
I almost forgot, contour stock battery life wins.
They are both great cameras It mostly boils down to: will you be using it underwater (gopro), side or top view (you can flat mount the contour on top of your helmet and adjust the lens to the side), does ease of use matter and if you need all the fancy mounts.