One thing that seems clear: without 2004, this year's team would have had a much more difficult time managing expectations both during the year, and especially in the post-season.
There are the obvious similarities between '04 and '07: the core of the lineup for both teams is and was -- in John Kerry's immortal words -- "Manny Ortiz"; the back-to-back power and on-base percentage has been duplicated very rarely in baseball history, most famously by Ruth and Gehrig in the late 1920s. Curt Schilling anchored both pitching staffs, although in 2004 (his first year in Boston, at age 37) he was still a power pitcher, with 8.05 Ks per 9 innings, while in 2007 he was down to just 6.02 K/9IP. Behind the plate, Jason Varitek remains the same, although his productivity has dropped (OPS down to .788 from a career high .872 in 2004), as would be expected from a catcher now 35 years old and with plenty of miles on the odometer.
But the entire infield has been turned over, and the 2007 team is clearly younger than the 2004 team (although less than one might think, with average age of 30.5 in 2004, and 30.1 years in 2007). More important, the 2007 team has young, home-grown talent in key positions: CF Jacoby Ellsbury, 2B Dustin Pedroia, closer Jonathan Papelbon, and 1B Kevin Youkilis, as well as pitchers Jon Lester, Clay Buchholz, and Manny Delcarmen. In contrast, the most prominent product of the Sox farm system on the 2004 team was Trot Nixon, although he was already a grizzled dirt dog by that time.
In the years since 2004, it has become clear that some players -- Edgar Renteria and Matt Clement leap immediately to mind, although the jury is still out on Coco Crisp, Julio Lugo, and J.D. Drew -- have trouble making the leap to playing in (i) the American League; and/or (ii) the fishbowl of Boston.
What's missing from this year's team are the "Idiots" -- most prominently, Johnny Damon and Kevin Millar -- who were both outspoken veterans who kept the media on its toes and the clubhouse loose. Millar, in particular, apparently rubbed some on the team the wrong way, but there's no question that for a team with high expectations (the 2003 team was 5 outs away from the World Series), the veterans were important. Manny, interestingly, seemed to try to take on the "Idiot" role with his we'll-win-next-year comments (on the off-day) after Game 4 of this year's 2007 ALCS.
Finally, although it's difficult to remember today, there was an ongoing debate in 2004 about whether a World Series victory without an ALCS championship over the hated Yankees would still 'count':
No one seemed to worry too much about the Yankees this year.
That's what is so disappointing about this situation. In the aftermath of the brainlock by He Who Must Not Be Named, which kept the Red Sox out of the 2003 World Series, the 2004 Boston baseball season was viewed by all as a go-for-broke endeavor. Acquire a stopper and a closer, spend money, let the free agents play hard in their walk years, and trade Nomar if you have to. Go for it.
And just about everyone bought into it. The Nation wanted the Yankees. Merely winning a World Series wasn't enough. The road had to go through the Bronx.