Nice solid team.
I would try to trade Helton for a Pitcher, then trade Sheets for a closer. I'm starting to belive that Sheets was a 1 year wonder. Your bench looks deep, with Bonds, Morneau and Wilson. Your only weakness is your closing, but an overall great team.
I would suggest trying to go after top closers. Like Foulke, K-Rod, Benetiz, or Izzy. I'm not sold on Gagnes heath, but if you are then you should go after him. A nice sleeper is Klob on the Braves. You might be able to get him for cheep.