They really need harsher penalties for failed tests. Ruiz was just an OK hitter and all of a sudden, last year, he starts mashing. At 33, he has his first monster offensive year. Surprise - he fails a drug test. Now, he gets suspended. But he will still get his money in arbitration - way more than he would have if he continued to hit like an average-ish hitter.
Melky gets caught and gets a 2 year contract worth millions.
Where is the disincentive to cheat here? Why wouldn't terrible players cheat to become average players, and why woulnd't average players cheat to become good players? A 25 or 50 game suspension is a small price to pay for setting yourself and your family up for life with one big contract.
edit - here are Ruiz's career stats. There are 2 big jumps apparent. http://www.baseball-reference.com/players/r/ruizca01.shtml