I couldn't read this and not comment. I had the same problem when I was a teenager. I was very responsible, I understood consequences, knew that my parents could be late for work, I could miss the bus etc. .. And it just didn't matter because I was too tired to be reasonable in the mornings. I couldn't make myself make the right decision b/c sleep felt so good!
I like the PP suggestion to help him wake up gradually, spend five-ten minutes in there talking to him, instead of coming and going several times. That way he won't fall back asleep and will get a few minutes to waken "less painful" way. If you keep coming and going it's just going to make his urge to go back to sleep stronger. I have read before that teenagers have a biological internal rhythm that makes them want to sleep in.
DS1 - 11/09
DS2 - 7/11