Whether or not the Sox land Matsuzaka is still unclear (could you imagine the reaction in Red Sox Nation if they didn't?), but they will get some help from Japan's Nippon Professional Baseball League.
They signed lefty reliever Hideki Okajima for two guaranteed years worth $2.5M total. Okajima will be 31 next season and will probably be used as a situational lefty, and perhaps a set-up man against predominantly lefty batters in late innings.
I think this a great pickup for the Sox. If it doesn't work out, we only lose $2.5M, a pittance compared to the other deals we're on the verge of making. And if it does work out, we land a solid lefty out of the bullpen. He also might help Matsuzaka adjust to American baseball and American life. The two can compare notes on MLB hitters and compare MLB hitters to NPB hitters.
This offseason has seen several Japanese players being taken by MLB teams. In the next few seasons, I think we'll see more and more of this. I think there will also eventually be a negative reaction towards this on the part of both MLB and NPB. As far as MLB is concerned, the big market teams have a huge advantage in getting Japanese players. They're free agents with transfer fees and teams like us and the Yankees have the capital and the budget to shell out large posting fees on risky acquisitions. Other teams do not. NPB will see more and more of its talent leaving for America and might try to stifle the flow of players.
I think many, many years from now, like 30, 40, or 60 years from now MLB and NPB will merge into one league with teams across Asia, and the Americas. But until then, I think there might be some sort of limit imposed on MLB teams "raiding" NPB rosters, and you might see something like a luxury tax imposed on posting fees in order to give some $$$ to smaller market teams so that they might benefit somewhat from the addition of Japanese ballplayers.