Funny that people are expecting a sophomore slump for Pedroia. No one would have guessed it back in April when he batted below the Mendoza line and had an OPS of .544. But at the time, his BABIP suggested a huge turnaround, and it was correct. Pedroia had incredibly bad luck in April, getting only one hit for every five balls that he put into play (about 50% below normal).
Given how accurate the use of BABIP was then, I'll use it again to see what can be expected of Pedroia in 2008. Overall in 2007, Dusty had a BABIP of .340. This was significantly higher than his Expected BABIP of .305, so it's probably fair to expect a regression in Pedroia's 2007 batting average of .317. I expect that he'll probably hit more like .300 next year.
At the same time, however, there may be a reason to expect his OBP to increase. Pedroia either drew a walk or struck out freakishly infrequently in 2007. He only drew a walk in 8.2 percent of his bats, which is low for him. The pitches he saw per plate appearance was the lowest among all Red Sox with at least 400 at bats. I'm sure Dave Magadan will work with him on that, and typically the more pitches a hitter sees per at bat, the more walks and strikeouts they get.
So overall, I'd expect a decrease in average and an increase in OPS. That's pretty typical of rookies. Pitchers generally learn to pitch to the weak spots of them and the actual rookies better learn how to get on base and drive major league pitches. There aren't any real red flags in Pedroia's numbers. He frequently makes contact and he doesn't strike out much. While he was lucky, he wasn't freakishly lucky like B.J. Upton was last year.