I made it about 15 minutes barefoot on pavement last night. What's interesting about this type of running is that it is very much a learning experience. Every time out you have an opportunity to play with different variables - correcting posture, cadence, etc. It's pretty easy to tell what works and what doesn't, because if it doesn't work it hurts!
For example, I have often read about a "late pull" being a problem in Pose running. In this situation, the runner is pulling his foot up after his body mass has significantly moved ahead. In Pose, you do drills to correct this. In barefoot running, I'm learning that if you have a late pull then you get some abrasion on on the ball of your foot as you push off. So if you continue to run incorrectly in this way, then your skin will eventually limit you. In this way, the body forces you to make corrections.