I learned how to drive in Alberta, and we were given a lot of information about which animals are bad to hit in a car. The worst is apparently a pig, since "it's low to the ground and solid -- like hitting a brick wall". For a moose, the dangerous part is the legs, since they can flip up and over and come straight through the windshield at you. I'd imagine that wouldn't be so much of an issue on a bike. At best you can swerve around it or duck under it (if it's tall enough), at worst, you would probably just bounce off it.

Edit: having read trickdog's post again, that sounds like a more likely explanation of what happens when you hit a moose in the legs. Either way, bad for the moose and worse for you.