My suggestion: Sit down as a family. Tell your son (and any other children) that it is not fair that "so and so" is late for work/school, or that you do not like feeling rushed and worried, so you will be doing things differently. First, you will not tell your son to brush his teeth, etc. When it is time to get in the car or catch the bus, he will go to school exactly as he is. (He may have to take shoes and socks with him.) If he misses the bus -- make him walk if it is less than a mile. (I followed my six-year-old in the car to make sure she was safe. She never missed the bus again!) If walking is not a possibility, keep him isolated at home/work with no TV and no contact with others the entire day. If he forgets his homework or his lunch, don't take it to him.
I am sure you can think of some pretty creative, natural consequences for his dawdling. The most important task you have is following through on the consequences and reminding him about the responsibilities that he has as part of the family.
The other side of the coin is to give him strokes when he does do things without reminders and some surprise rewards from time to time. Tell him how much you appreciate how responsible he is, how doing what he should helps his parents, and how good it makes you feel.
All of this will help your son accept responsibility, and give him control over his own actions and not over your family.