I fit into this category. I was taking summer school at the local community college so that I could take AP classes the follow school year.
In California, we have an exam called the High School equivalency exam. I took this test at 16, and by the time I was 17 I was a college freshman.
On top of that, the school I went to was on the trimester system, so I had a Bachelors of Science by the time I was 20.
My HS classmates at that time were probably in their second year in college by that time.
I would have greatly appreciated having the opportunity to "Walk" with graduating class that year (or what would have been my year), it sounds like this plan would allow over-achievers like myself to have the best of both worlds.