As has been discussed to death, there are few power-hitting outfielders available, even if the Cubs were looking to move Kosuke to centerfield. 

I propose something different: a power-hitting second-baseman.

Rich Hill and Matt Murton for Kelly Johnson and Royce Ring. 

Atlanta is playing well, but has a need at starting pitcher.  They are loaded with LH power, with Jones, Teixiera, and McCann. Even Kotsay and Gregor Blanco are adding OBA from the left side.  One of their prime prospects is Brent Lillibridge, currently a SS.  They have an assortment of other potential 2Bmen: Ruben Gotay, Martin Prado, Omar Infante.  Matt Diaz, their RH-hitting LFer, is struggling with a below-.600 OPS. 

The Cubs could bat Johnson in the lower part of the order, with Fukudome moving up to the #2 spot.  Kelly has had some minor injury problems, but DeRosa could play against lefties or fill in as needed.  Now DeRosa has hit very well this year, but could see more regular time in RF, or just be the top bench guy. 

I'm interested in your analysis. 

 UPDATE:  Thanks for all the discussion.  By the way, Matt Diaz went on the DL after being injured last night.  The Braves might have some interest in Murton in a minor deal.