Well, with the wacky Japanese baseball rules, a player has to put in ten years of service time in the Japanese big league before he can become a free agent and come to the states. For most players, that means that they are 33 or 34 years old, which is the downside of their career. Ichiro started playing in the bigs when he was 17, so he came over in his prime. Johjima started in the Japanese bigs at 20, so he's still got some mileage left on his tires. The only guys that are likely to make it to the US Majors are either the superstar, freak-talents like Ichiro, Matsui or Johjima that can start at 18, 19 or 20 years old or guys on the downside of their career that can be effective, fairly cheap roster fillers.
Next year, though, watch out. The best pitcher in the history of the Japanese majors is probably going to be posted. Matsuzaka is his name and the guy is a pitching machine. He won the MVP of the WBC and is positively sick. He pitched a 170 pitch, complete game shutout in high school and then came back and pitched another five innings two days later. He's got a mid 90's fastball and an array of breaking balls that he can throw, throw, throw. The Yankees, Mariners, Dodgers, Red Sox and every other high revenue club have been scouting him for a few years now. Having Ichiro and Johjima on the team probably makes the M's the favorite to land him. The thought of he and Felix at the top of the Mariner rotation from 2007-2011 makes me positively giddy.
We could have the best leadoff man, the best catcher and the best pitcher in the history of the Japanese league playing for the Mariners next year. Woot!