Everybody is making good points and let's face it, what might be the best for one kid might not be the best for another. That said...
If my son were drafted in the first round...Go! Not because it's life changing money, but because the team is heavily invested and it's in their best interest for you to succeed. If you decide to go to college, the chances that you drop out of the first round are a lot better than improving your stock and of course, you could get injured. Gotta go.
The drop off between those that make it to the bigs from the first round to the second is pretty drastic and I certainly wouldn't feel as comfortable, but I'd be okay with it.
It's the third and fourth round where it would be a painful decision, after that I'd prefer he go the college route. If he got drafted in the third, fourth round we'd just have to sit down and have a heart to heart, hopefully we've already done that and come to a decision before the draft, a number where he, me and ma are comfortable, 90th pick, middle of the third round...below that it's school or something like that and try to blow off the glamour of "being drafted" and not let our emotions takeover whether the result is good, or bad.
Ultimately, he's going to do what he wants to do and of course it's his life, I certainly wouldn't want my now 24 year old son to be angry that ma and I didn't allow him to pursue his dream. It's a tough one.
If my son doesn't pick up a bat and glove pretty soon, I won't have to worry about it at all. I'll let yawl know in 11 years how it turns out.