I expected them to at least contend for a playoff spot. If my expectations have changed at all, they have gone up. Especially with the current Yankees slide over the past 2-3 weeks, I think the Sox can easily win the division by 5 or so games over the Yankees and Orioles.
This team is different. Even on nights when they face pitchers like Price, Sabathia, and Lee (just using actual games from this season), they get them out of the game by the 7th, giving them a chance to come back. The reason why they are in these games s their own pitching. Buchholz is the AL Cy Young, no doubt about it. Lester has been primarily good, but with some bad starts. Lackey has a low ERA, but no run support. Dempster and Doubront have been good when they need to be. Even Aceves has come up big in the spot starts he has made. Pitching has kept the Sox in games, giving their offense a chance, even when they are not having a bad night. Take last Thursday against the Rangers as an example. The Sox left 10 men on base through 6, but Lester had a quality start to keep them in the game, and Ortiz eventually won it. Last year, that never would have happened.
That is why this team is winning games. They know they're not perfect, so they play to they're strengths. It has been ridiculously fun to watch so far.