Kazmir has been one of the best pitchers in the league since he took over full time in Tampa Bay's rotation. Until 2008, Kazmir was pretty much the lone bright spot on the Devil Rays (then the Rays) roster.
Kazmir originally came to Tampa Bay after the New York Mets traded him for a pitcher by the name Victor Zambrano. Zambrano wasn't good for the Mets while Kazmir turned into an ace. This trade went down as one of the most lopsided ever.
But now Kazmir is headed to the Angels to help them secure the AL West. Kazmir's 2009 season has been a step down from his 2008 one. He went 12-8 with a 3.49 ERA, a WHIP of 1.54 and an opponent's batting average of .220 in '08 while going 8-7 with a 5.92 ERA and a WHIP of 1.64 and an opponent's batting average of .273 this season. A huge step down.
The Red Sox have been in need of a left handed pitcher. They recently acquired lefty reliever Billy Wagner from the Mets for minor leaguer Chris Carter, but he has Eric Gagne written all over him.
The likely reason why the Red Sox weren't linked to Kazmir is either A: The Red Sox weren't interested (I doubt that) or B: The Rays and Red Sox didn't want to help each other out.
The Rays and Sox have been a full blown rivalry since Coco Crisp charged James Shields in that fight last season, and the increasing tension during the 2008 ALCS. The Red Sox likely didn't want to send the prospects needed to pry Kazmir away to a division rival, and the Rays don't want to send their ace to their main division rivals.
Kazmir would be a help, but it might cost some good prospects (Stolmy Pimentel, Yamaico Navarro), and watching them thrive in Tampa might kill Theo Epstein.
Plus, Kazmir might be in a downward spiral for the rest of his career, starting now. If Pimentel and Navarro ended up being good players, this deal would end up being extremely lopsided.