Washington's 2012 season came a year early. Most fans expected the Nationals to contend in 2013, and that 2012 would be more of a stepping stone year. Of course, the team had the best record in baseball during the regular season and boosted expectations for fans of the franchise.
Contrary to popular belief (mostly in the minds of angry NL East fans), 2012 wasn't some sort of fluke for Washington. This is an extremely talented team, and they're going to be even better in 2013. The one significant free agent on the team is starting pitcher Edwin Jackson. The team could use another starting pitcher with Jackson departing and the potential non-tendering of third year arbitration eligible player John Lannan. The team also has an interesting decision at first base, where Adam LaRoche is a free agent, but left fielder Michael Morse is so putrid defensively that he'd be a better fit there. The team might pursue a middle reliever or two with Sean Burnett and Mike Gonzalez hitting free agency, but I don't think they'd consider a big name like Rafael Soriano or Ryan Madson.
This team has been craving a center fielder for awhile, and if they don't bring LaRoche back, a game of musical chairs could take place with Morse moving to first base, Bryce Harper shifting from center field to left field, and the Nationals hunting down a center fielder. The team apparently covets Michael Bourn, and his agent Scott Boras has several clients with Washington, meaning that Washington could be a great fit for the former Brave. BJ Upton has also been linked to the team in the past, and he could be a fit with the team as well. I honestly think that it's LaRoche or a center fielder for this team, and that they're not going to explore another first baseman or a corner outfielder. As for the slot in the rotation that may be available, I think Washington would explore a veteran innings eater in the mold of Jackson if they let Lannan walk. Think of a Joe Blanton type of player. However, signing a player like Shaun Marcum to a one-year deal in the same vein as they did with Jackson if he can't get what he's looking for might work out very well for them.
Because of the relative youth of this team, I don't see them being very active in the trade market, especially when it comes to spinning off pieces of the major league roster. The only player in the majors I could see the team looking to deal is Morse, making $7 million in 2013. Washington could feel that the team could be in a better shape offensively and defensively by bringing in a center fielder and re-signing LaRoche, making Morse the odd man out. He'll be 31 in March, so he's not exactly a spring chicken in comparison to the rest of this team.
Again, I don't see the team making much headway in the way of trades, especially after their farm system took a huge hit with the Gio Gonzalez trade last winter. One possibility that Washington has seemingly been perpetually tied to is Denard Span of the Twins, who was rumored to be heading to Washington at the 2011 trade deadline (so much so that we had a post in the hopper ready to go live if the trade became official). Span is under contract through 2014 with an option for 2015, meaning that he'd be more of a long-term trade for the team that wouldn't cripple their payroll. Aside from him, I haven't heard any rumblings of Washington making a trade, but that doesn't mean one won't happen at all.