I think I've seen similar cases, although not for as much money - and not including money to cover lost potential earnings. I think they've all ended pretty much the same way as this one, or possibly settled out of court. You're right that this could cause trouble - it could shut down local racing. One lawsuit could bankrupt a track and scare other tracks into closing.
When we sign in to race we know the potential consequences. I feel bad for Mr. Westbrook's injuries, but I don't buy his argument that the form he signed was invalid and that the track should pay him for pain and suffering. He was a seasoned veteran who knew what can happen in a Sprint Car at Williams Grove.
Racers, the verdict points out two things that I hope you're already doing. One is to find out what (if any) insurance your track has, as well as the procedure for enacting it if you need to. The second is to carry your own insurance so you don't have to rely on the track or somebody else. (Third, I suggest checking out the track EMS and safety crews - are they trained to help you after a wreck? Do they have adequate equipment?) In the end it's your well-being at stake, as well as the well-beings of your family.