The Brewers starting pitchers have been the biggest difference between the last couple of years and the dark ages in the late '90's.  No more Rafeal Roque opening day assignments here.  The following is a summary of how many started the Brewers have used and their composite ERA the last 10 years.

          Number of           
Year   Starters Used   ERA
2006        12            4.73
2005          8            4.02
2004        12            4.21
2003        12            5.48
2002        13            5.18
2001        13            5.13
2000        12            5.09
1999          9            5.22
1998        10            5.01
1997        10            4.48

Looking at this we should expect about 10 pitchers to get starts for the Crew this year.  By my estimation this would most likely include:  Sheets, Capuano, Bush, Suppan, Vargas, Villanueva, Jackson, Gallardo, and two others.

Now take a look at what the Crew has gotten out of its top 5 starters the last 10 years.  The "top 5" is considered the five pitchers who started the most games each year.
    Games Started     ERA   WHIP   K/9 IP  
2006         135        4.36    1.28    7.12  (Capuano, Davis, Bush, Ohka, Sheets)   
2005         136        4.07    1.35    7.21  (Capuano, Davis, Santos, Sheets, Ohka)   
2004         133        3.92    1.28    7.60  (Davis, Sheets, Santos, Obermueller, Capuano)   
2003         129        5.39    1.49    6.22  (Franklin, Sheets, Kinney, Rusch, Obermueller)   
2002         124        4.85    1.52    6.36  (Rusch, Sheets, Quevedo, Wright, Neugebauer)   
2001         122        5.06    1.52    5.75  (Wright, Haynes, Sheets, Levrault, Rigdon)   
2000         124        4.58    1.51    5.31  (Haynes, Wright, D'Amico, Snyder, Bere)   
1999         121        5.07    1.52    5.35  (Karl, Woodard, Nomo, Pulsipher, Abbott)   
1998         126        4.85    1.48    6.02  (Karl, Woodard, Juden, Eldred, Woodall)   
1997         133        4.43    1.35    5.71  (Eldred, Karl, D'Amico, Mercedes, McDonald)   

Two things that stand out here to me.  First, every year about 30 starts are going to come from people other than the top 5.  Second, look at the marked difference the last three years.

One other startling fact about the Brewers pitching the last 15 years...from 1990 thru 2002 exactly two Brewer pitchers struck out 150 batters in a single season (Eldred '93 and Nomo).  The Brewers even had two seasons (albeit the strike shortened '94 & '95) where not a single pitcher broke 100 K's.  In comparison since 2002 nine pitchers have had 150 K's in a season (Sheets three times, Capuano twice, Davis three times, and Bush)