Or in other words, the Pirates committed highway robbery. So much for Kevin Frandsen and John Bowker, the Giants traded away their second best pitching prospect. I think Giants fans would like to perform True Blue's all-time best headline on Brian Sabean right now.
Alderson got a B+ from John Sickels of Minor League Ball, better than any Dodger prospect except James McDonald. Alderson doesn't have great stuff but he has impeccable command. Splitting the year between High-A and Double-A the 20 year-old Alderson has a 66/17 K/BB ratio in 98.2 innings.
I think this comment at Fangraphs sums up the situation nicely, "The best pitching prospect of the day doesn't get traded for Cliff Lee, but for Freddy Sanchez. Awesome. Nice job, Cleveland."