If Carlos Zambrano and his people weren't already entertaining $100 million daydreams, the Barry Zito signing ensures that they now are.
Zambrano is three years Zito's junior, strikes out more than Zito (8 K's/9 IP vs. 6.9 K's), throws fewer gopher balls (.69 HR's/9 IP vs. .93 HR's, even with Z pitching in Wrigley and Zito in the Coliseum!) and has pitched to a better ERA (133 ERA+ vs. 127).
In his years as a starter, Zambrano has shown himself to be nearly as durable as Zito (though admittedly, Zito has been around a little longer).
Finally, though I don't have the data to prove it, I would guess that long-term, a power pitcher like Zambrano is going to age better than a curveball pitcher like Zito.
When the Cubs set off on the spending binge that landed Ramirez, Soriano, Lilly, Marquis and DeRosa, they had to know that the day would come when Zambrano would ask the $100 million+ question:
"What about me?"
They had to have figured that into their long-term budgeting, so a year from now, we didn't have more invested in Ted Lilly than in any other pitcher on our staff.
They had to be thinking about those things.