Lin is making a seamless transition to Double-A this year. While he has not yet developed power, his on-base skills continue to impress (.383 OBP). When you factor in his speed and defense (above average range and arm), I think we are looking at the Red Sox long term player in CF.
In fact, Lin could be ready to start in CF for the Red Sox in 2011. Though, that might be rushing things. A more likely scenario: Lin begins the 2011 season in Triple-A and will be promoted during the season and used as a 4th outfielder and might even share some playing time with Cameron in CF. I would expect Lin to be the Red Sox starting CF in 2012.
With Lin's development, Ellsbury is becoming more and more expendable. Lin is a better defensive player, with a stronger arm, and Lin has more potential in terms of plate discipline, an aspect of Ellsbury's game that has not improved: his OBP has remained steady relative to his BA with little or no improvement in #P/PA, O-Swing%, and Z-Swing%. I suppose Ellsbury could start in LF next year, but I prefer OPS guys in the corners.
Lin has exactly 6 extra base hits this year (4 2B, 2 HR) in 232 AB +35 BB, which gives something like 267 PA or a bit more depending on how many sacrifices he has. Against lefthanders, he has exactly 0 extra base hits. As for his speed, he has 7 SB and 9 CS, so speedy as he is, he isn't yet using it effectively on the basepaths. I really want to see Lin succeed, Hwa Lien, his home town, is one of my favorite small cities. (The coastal road from Taipei to Hwa Lien is one of the most beautiful drives in the world, it is cut out of the rock half way up a cliff, and it used to be just one lane, with traffic allowed one way in the morning, then the opposite way in the evening. A frightening drive, but an amazing one.) But maybe we better hold off a while on writing Elsbury's ticket out of town.