Like many posters here have suggested this is a really good team so I wouldn't make too many changes.
1.Resign LaRoche to a 2 year deal with an option for a third.
2. Let Jackson go and go hard after Greinke/Haren/Trade for Price
3. Trade Morse for prospects.
4. Sign Bourn/Upton.
5. Extensions for Zimmermann and Desmond.
6. Sign a veteran back end reliever Madson/Broxton
This is my dream offseason but really unlikely to happen. I can completely see the Nats not doing much at all and wait to see some of the young studs develop like Rendon/Meyer/Goodwin, all of which I expect to called up at some point next year if they are not traded. Either route is fine with me though. Expecting another 95+ win season in 2013