Thanks to WGC, who posted this in the comments:

"The stark truth (known by all close followers of Cuban baseball) is that Juan Yasser Serrano was a rather mediocre Cuban Leaguer whose 2007-2008 record was a below average 2-7 won-lost mark, further diminished by an elevated 6.46 ERA and a hefty .312 opponents' batting average against his deliveries. And this, while hurling for one of the league's very best teams, Villa Clara. Serrano's three-year lifetime mark entering the current campaign was 14-16, with a 4.40 ERA for a club that captured division titles in all three seasons he labored there. It is hard to imagine a young prospect as being one of the most notable talents on the island when last season he posted the third worst ERA on his own team's 15-man pitching staff."

That info is taken from this article.  The article sets out to criticize the agent for Serrano and does a find job at it.  The part that concerns me (a Cubs fan) isn't the agent, but the fact that Serrano isn't even good at Cuban baseball.  The Cubs only gave him $250,000, but it sounds like it would have been as good of an investment to give me that money to play baseball for them.

Why would you even waste this money?  This is the equivalent of buying 250,000 lottery tickets for last week's lotto.

Doc Blume also has this info up on his blog.