The 2012 Dodgers started out like a house of fire....and then hit the wall once Matt Kemp went down with hamstring issues, missing most of May and June. The team eventually ceded their NL West lead to the World Champion Giants, despite a summer spending spree that saw them acquire Hanley Ramirez, Josh Beckett, Adrian Gonzalez, Carl Crawford, Joe Blanton, and Shane Victorino.
The Dodgers are put together pretty well going into 2013. All three of their outfielders (Kemp, Crawford, and Andre Ethier) are all signed long-term, and the team also doesn't need to worry about corner infielders with the presence of Gonzalez and Ramirez. I'd imagine the team will make something work at the middle infield positions with Dee Gordon, Mark Ellis, Nick Punto, Juan Uribe, and Jerry Hairston all signed for next season (and beyond, in the case of Gordon). The Dodgers could use another starting pitcher due to the injury issues with Clayton Kershaw (hip) and Chad Billingsley (elbow, potential Tommy John surgery), and because of Chris Capuano and Aaron Harang aging.
When it comes to the starting rotation, I don't think the Dodgers are going to spare any expense, especially if Kershaw or Billingsley will be missing significant time due to their injuries. Angels free agents Zack Greinke and Dan Haren would probably be both in play, along with Anibal Sanchez (a long-time teammate of Ramirez, who were both part of the same trade that sent Beckett to Boston). Adding one of those guys to the quartet of Kershaw, Billingsley, Beckett, and one of Harang or Capuano would be a pretty fearsome rotation, but one that's also very frail considering the current injuries of Kershaw and Billingsley, and Beckett's consistent blister problems throughout his career.
I'm going to go out on a limb and say that Los Angeles GM Ned Coletti is done dealing after taking a blowtorch to his farm system this summer. LA's farm system is essentially Zach Lee, Yasiel Puig, and no other top tier talent after Coletti dealt away Rubby de la Rosa, Allen Webster, and Ethan Martin (among several others) in loading up the Dodgers with veterans. As for current players on the roster that the team could deal...I really can't think of any, especially with outfielders Victorino, Bobby Abreu, and (probably) Juan Rivera hitting free agency.
Again, I really don't think the Dodgers are going to be looking to pick anyone up this offseason in a trade. The team's biggest needs come in regards to the pitching staff, and with the way that the free agent market looks, the team would probably be better off throwing heaps of money at free agents as opposed to dealing even more younger players and completely destroying their farm system.