Wheels are going to break on luggage, it's just going to happen. If it's going to cause distress I would just make sure I always buy luggage with somesort of life time warranty. How can the airlines possibly know that the wheel wasn't already broken when you checked it. If they did compensate for this, what's to stop someone from just checking their luggage that one final time after it breaks, complaining about it and getting a new bag or atleast a downpayment on a new bag from the airline?
I can't believe some people think this is worthy of small claims court. (Then again, I don't really find much that is).