You have a great offense with very little room for improvement. My only concern is Durazo. He has historically had health problems and has never been relied upon to start for a full season. I believe he'll be successful this year in Oakland, but just watch him closely. If he starts out hot, you may want to see what you can get for him, as you never know if he'll be able to keep it up all season long.
Your top starters are excellent and you should have no problems getting saves. However, the middle and bottom of your rotation scare me a bit. I think it's awfully risky to count on Lopez, Ortiz, Lawrence, Fossum, and Lackey behind your top two. Lopez was good last year, but can he do it again? Will Ortiz handle the transition to Atlanta? Lawrence was good last year, but still plays for a below average team in the competitive NL West (lots of games in Coors!). Fossum and Lackey are good risks at the bottom of the rotation, but it seems like you might be relying on them too heavily with all the question marks in front of them.
I would look to trade from your strength, offense
, in order to improve your pitching. A-Rod has health concerns, but I'll bet some owner will take a chance on him and give up his starting shortstop along with a strong starting pitcher. Your outfield is really strong, and you may be able to move one of your outfielders for another top of the line starting pitcher. By rounding out your team, you'll have a much better shot at success!
Please comment on my roster here