See, this is where there is a difference in fielding that nobody really talks about. You can't just say that Mike Cameron is a good defensive outfielder, therefore he will be a good leftfielder in Fenway. You don't necessarily have to be a great defender. You just have to learn how to play the wall and the corner. Heck, even Manny learned the ricochets to an extent.
I really don't mind Cameron being the everyday LF in 2010. I think that he is a great defender and can still knock in some runs. The problem I have is that he's only around for one more year and our current DH is only signed for one more year. I think it makes some sense to sign a guy like Ordonez now to play some OF this season and then take over as the everyday DH in 2011.
First of all, let's not forget that Mike Cameron will be 38. Who's offensive numbers are more likely to decrease due to age? Secondly, Ordonez has morphed from a power hitter in his prime to an outstanding contact hitter who has some power. He has changed his game almost in the same way that fireball pitchers can turn into finesse pitchers later in their careers. I don't think there is reason to believe that his offensive numbers will decline dramatically over the next 3 seasons.