Beltre baby...most valuable to his team.
Rolen's rolling, but he's got superb protection and a lot of his success has come due to the supporting cast around him. With Pujols' recent surge, an argument could be made for him, too.
Simply, the Cards still could make the playoffs without Rolen. The Dodgers could be in third without Beltre.
Now, the most valuable argument...why not Bonds? Because his team isn't even in the playoffs. I don't care if he's more valuable...but his team isn't there. Beltre's stats aren't that far off, so you've gotta go with Adrian here. If there was a substantive difference, I may change my opinion. But there isn't that big a difference. Now, if the Giants make the playoffs, I'd probably go with Barry. But, I see the Cubbies, Stros, or Marlins picking up the Wild Card.