Here are where some of the Nats 2009 offensive seasons ranked in their careers (by OPS+)
Ryan Zimmerman - best of his career
Josh Willingham - best
Nyjer Morgan - best
Adam Dunn - second best
Adam Kennedy - best since 2004.
This is not saying that they all are going to regress significantly. Willingham and Dunn were not that far off what you'd expect. This was Morgan's first full time season. Zimmerman is young and good enough he might get even better. But it is possible that they could all go down a little and everyone taking a step back is as bad having a couple of key injuries. Who are they looking at then to maybe provide a spark by bouncing back from a bad year then?
Cristian Guzman - 4th best. (no seriously - look it up. He had a bunch of AWWWWWFUL seasons in the past)
To be fair his 2009 was way worse than 2008 or 2007. Still, he was above his career average and is going to be 32.
Pudge Rodriguez - worst.
But that was expected from a 38yr old catcher who hasn't had a good offensive year since 2004.
Elijah Dukes - Middle of 3 years.
First season playing more than half in the majors. He took a big step back from 2008.
Now do you see why Elijah is the key? If you don't believe he can bounce back a little to about average, the fate of the offense may rely on Guzman and Pudge having significantly better years. That's a AMC Fear Friday movie if I ever saw one (especially since they've aired Terminator 2 and Ghostbusters 2 in that spot. Seriously guys. Seriously.)
[Personally I like Zimmerman to have a better year and at least one of the three other main guys to match their 2009. That should be enough to stem the tide of the other ones dropping a bit unless one of Dukes or the Replacement-Level MI (Kennedy, Guzman, Pudge) is just truly useless. But a step back by the offense could happen and it shouldn't be a surprise]