1. He's an ace
2. Keep Kyle Drabek and Domenick Brown
3. He's signed through 2010...
4. ...at a reasonable rate
5. Hamels and Lee are a great 1-2 punch
6. The Phillies are now as good as anyone on paper
7. Keep JA Happ
8. Keep Michael Taylor
9. Ben Francisco is a solid right handed bat (even if he's a weak defender)
But you know why I like it: because Lee does not give up home runs. In 152 innings this season, Lee has only given up 10 home runs and in 223 innings last season, Lee only gave up 12 home runs.
In addition, according to fangraphs, Lee's flyball % this season is a very manageable 35% and his HR/FB rate is only 5.8% this season.
Why are home runs and flyballs so important with Lee? Because the Phillies play in the hitter friendly Citizens Bank Ballpark, which is a bandbox second to only the new Yankee Stadium. It's vital that the Phillies have pitchers, who are not prone to the longball because that type of pitcher has a high probability of getting hit hard in Citizens Bank Park.
There is no guarantee that these stats will lead to wins for Lee, but this a great risk for the Phillies and gives them a deep rotation to balance out a strong and balanced offense.