I think all UFC fights should be scheduled for 5 rounds. The UFC is the big league, and its fighters should be ready to go the distance. For now it should at least be 5 rounds for top contender fights. The Lesnar/Junior fight would be a great time for the UFC to introduce 5 round non title fights. A fan can only wish. Thoughts?
Injuries do occasionally happen in fights. I think if the fighter is not ready to take the risk of a five round fight then they are not ready for the UFC.