I spent my last two years of high school at the community college (our program allows Jr’s and Sr’s to go full-time). Best thing I ever did in my entire education. I picked up my high school diploma and my AAS (with honors) the same week. I will encourage my children to do the same.
High school in its current form should be abolished. I would be in favor of a new "high school" consisting of grades 8 thru 10. At the completion of 10th grade, a student would either go to junior college (if qualified), trade school, or out into the work force. In junior college, the student could get a better idea of what he wants to major in, and what college he wants to get his Bachelors from (and senior college would thus be reduced to 2 or 3 years, depending on whether the student wanted a masters)