Don Wakamatsu won't be the only coach breaking new ground in 2009; the Dodgers have hired former Yokohama BayStars manager Daisuke Yamashita to coach in their minor league system. From what I gather, Yamashita will spend most of his time at the rookie ball level in Arizona. JapanBall has the English-language Kyodo write-up of the news, but but I think their translation of his quote misses the eloquence of his original comment in Japanese. So I translated it myself:
"I played US-Japan college baseball at Dodger Stadium, and 35 years later I have another bond with the Dodgers. This time, I want to be an asset to the young players aiming for an American Dream."
The only other former Japanese player/coach that has coached in an MLB organization is Denney Tomori. Denney pitched in the Boston organization in 2005 and re-joined the team after retiring, but I saw conflicting reports on whether he was a roving minor league pitching coach or a scouting advisor. Other coaches have spent short-term "foreign study" programs with US teams as well.
Good luck to Yamashita on his new position, and kudos to the Dodgers for thining outside the box with this hire.