Looking at their careers, their power numbers are similar. In fact, on the baseball-reference Lance Berkman page, the most similar players to Lance are:
David Ortiz (907)
Kevin Mitchell (893)
Albert Pujols (887)
Carlos Lee (884)
So far, Lance is a career .301 with 249 HR and 834 RBI. Berkman is signed for 3 + option = 4 more years after 2007.
Carlos Lee is a career .288 with 247 HR and 884 RBI. He is signed for 5 more years after 2007.
Both are 31 years old.
If Berkman and Lee both average 30 home runs over the next 4 seasons, they'll be around 370 career. I would venture to guess that neither will hit 500 home runs in their career, and both will fall short of the Hall of Fame.
It shows you, that in addition to everything else he did, just how good a home run hitter Jeff Bagwell was, for after the first 13 years of their careers, Berkman and Lee would both be well short of Bagwell's home run total. Assuming the 30 home run pace of course.