A guy I really like in the college ranks: third baseman Ryan Braun of the University of Miami-Florida.
Braun is hitting .417/.503/.736, with 11 homers, 20 steals, 26 walks, 25 strikeouts in 144 at-bats. All of these numbers are excellent. He is showing power, speed, and the ability to control the strike zone. Scouts are reportedly very impressed with him. He has both tools and skills, and should interest both stat-oriented and traditional scouting teams.
I do regard him as fantasy-draftable already, if your league has a large farm roster with long-term keepers and such.
UPDATE: Reader sdangler has posted a diary about Baylor RHP prospect Mark McCormick. Check it out there on the right hand side of the page.