Nothing has changed since my Barry Zito profile was published over at Baseball Prospectus, so I refer you to that for my view of Zito. One thing that I should say though, San Francisco definitely has a park built for Zito, although it is not as suited for him as Oakland's was due to having less foul ground. It should help reign his flyballs in about the same though, which will be important in keeping Zito somewhat effective. Of course, moving to the National League, which is more of a Three True Outcomes -- homeruns, walks, and strikeouts -- league is not going to help Zito, who gives up homeruns, walks a ton of batters and doesn't strike out many guys.
Giving any pitcher seven years is ludicrous though, even someone who has been as durable as Zito. If his arm falls apart after the heavy workload in Oakland, just like Mulder and Hudson's seem to have, the Giants will be even worse off than expected. If he does stay healthy, they have a #3 starter for the next few years, and I guess that's something. The money doesn't bother me so much, even though he's being overpaid for his services. I'm not sure where the idea of Zito as ace really came from, since he did not even deserve the one Cy Young award that he was selected for.
Here's the link to the profile; you decide if he's worth seven years, $126 million: