PG, I could swear I saw an article on your site yesterday about HS vs College players and the draft, but now I can't find it to save my life. It was very old (2009?) and from what I can recall, it compared two draft's worth of 1st round college players (48 total) to their original HS draft position before they elected to attend their respective schools. I believe the highest player picked originally went in the 4th round, while many of these players were undrafted out of HS.
The overall impression I got from the article was that virtually every player on the list improved their draft stock after 3 years of college.
It would be interesting to see an updated version of that article, say using the past two drafts and comparing those players to the HS versions of their draft slots.
Many/Some players going to college would have been very high draft picks had they not gone to college. Just because they were not drafted or drafted very low is not necessarily indicative of their athletic ability. Take the Freshman pitcher at LSU from Missouri. If I read article correctly, he was undrafted. He was undrafted because he said that he is going to college. Assuming no injuries, etc. He will be drafted in 2/3 years. A person could say that he went from being undrafted to highly drafted which is a true statement but very, very misleading.