The main difference of the 2009 Rockies and the 2007 Rockies is the caliber of their season as a whole, and not just how they did in September.
In 2007, the Rockies were a legitimately decent team, a mid 80s win team that happened to catch fire at the exact right time to finish at 90-63. A lot of people in Colorado thought 2008 would be the year of real emergence, with the team properly gelled and developed to a point where they could be competitors, but injury took hold of many key players on the Rockies and set back the anticipated "coming to fruition" of the farm team, and the ticking clock of Matt Holliday had everyone on edge.
What made 2009 special is the fact that come September, the Rockies weren't a magical longshot to take the postseason. They were legitimate contenders, in the thick of things, and had teams chasing them rather than the other way around. What made the team the strongest this year was surprisingly not the lineup, although they did score the 2nd most runs in the NL to the Phillies while posting the highest OPS+ at 108. No, the biggest strength for Colorado was its pitching staff. Posting an ERA+ of 106, FIP of 3.96, and tRA* of 4.08. What's most interesting about the pitching is that it isn't an Ace and a solid #2 deflating the staff ERA, it's a solid rotation from top to bottom. Ubaldo Jimenez is emerging as the first Ace in Rockies history; Aaron Cook - despite a rough year in general, featuring small injuries and mechanical problems - has been stellar his past 2 starts and looks to be in playoff form; Jorge De La Rosa has finally reined in some of his command issues and is top 10 in K/9; Jason Marquis, while shaky down the stretch, has rediscovered his sinker and can be counted on as a dependable mid-rotation starter again; Jason Hammel, castoff from Tampa Bay, has found his stride in Colorado and leads the Rockies pitching staff in K/BB at 3.17. Add the re-emergence of Huston Street as an elite closer and Rafael Betancourt as a solid setup man. Insert farmhands Franklin Morales and Matt Daley into the 7th inning and the Rockies have a pitching staff whose likes haven't ever been seen in Colorado.
Aside from the excellent pitching, the team is deep. We have enough starter-caliber players to form different lineups on different days to attack matchups from wherever, and then those that don't start become weapons off of the bench. Oh, and speaking of weapons off of the bench, we have an answer to your Matt Stairs: Jason Giambi.
The similarities between 2007 and 2009 are in the ways the team interacts within itself. It's still a very strong clubhouse, made mostly of homegrown players. It's the very definition of "Team". Additionally, it's a very strong defensive club, especially the infield, which caters to the strong groundballing emphasis that pitching coach Bob Apodaca puts on the team.
4. Which Rockies player needs to step up for them to defeat the Phillies?
Jason Marquis, number 1, with a bullet. I personally don't even want him starting, but with De La Rosa down for the count, we're gonna need him to pitch like the first half in a big way. Big, big way.
If the matchups play the way we expect them to, with Lee, Hamels, Happ, I'd say the guys who need to step up the most are Chris Iannetta and Brad Hawpe. Iannetta had a monstrous breakout year in 2008, to the tune of a .391 wOBA. He's hit the skids pretty hard this year, at least in terms of batting average, but his splits show a dominance against LHP, so I'd personally expect to see him starting at least 1 or 2 of these games, despite Torrealba's hotter hand. Brad Hawpe was a god of thunder the first half of the season, and it earned him an All Star invitation, where he was almost the NL hero. He's fallen on hard times as well, and regressed to his mean somethin' fierce. But he's been heating up the past couple of weeks, so here's hoping it's signs of things to come.
5. Which Phillies player worries you the most in a short series?
Brad Lidge. No, seriously, Cliff Lee. He doesn't walk guys, and that's a massive strength of the Rockies, taking the free base. He also has a good K/9, and that's a massive weakness of the Rockies, punching out. We'll probably have to see him 2x, and that'll make things really difficult.
6. Series outcome prediction.
Rockies in 4. We can steal one from Hamels and while it won't be a fun game, I think we can wear the rotation down in Coors and beat up on the bullpen.