I have been waiting patiently...
My Nationals are... they...
They have almost rendered me speechless... almost.
I do not see a weakness. Top to bottom.
Denard Span
(2013 MVP) Bryce Harper
Ryan Zimmerman
Adam Laroche
Jayson Werth
Ian Desmond
Danny Espinosa
Kurt Suzuki (or Wilson Ramos when fully healed)
Every spot but Span is a double digit home run potential, all but Suzuki being 20+, they have 4 guy who will likely be around 20+ SB. Everybodys gonna give you .270 plus. And a few bodys could give you a whole lot more. Zimmerman, Laroche, and Harper will probably all have 30+ HRs, Desmond may as well, and Espinosa and Werth should be in the 20+ range. I honestly have Harper as my MVP favorite right now in the NL. I think the improvement you saw in Mike Trout is the same as that you saw DURING last season for Harper, and he's going to be a .300/.400/.550+ beast next year with 30-30 thrown in, maybe 100 RBI and 120 R.
Defensively, they should be as good or better than any team in baseball. Period. Every outfielder is a sure glove with range and a good to great arm (Harper will have the best arm in the majors for a left-fielder). Every infielder has a sure glove with range and a good arm (Zimmerman's arm can be erratic, which is why bringing back the gold-glove Laroche was so important). Both catchers handle pitchers well, play their position well, and have excellent arms.
Then there is the pitching staff. Top to bottom the best in baseball, and maybe a historically good staff, depending on a couple factors. The main, most prominent, as it is for all teams, is health. If everyone stays healthy, this team has the potential to be historically stingy. You have a high strikeout, fantastic pitching staff, a fantastic defense behind them, and the ability to potentially have a lot of 6 inning games.
The starting rotation has the potential to be the best, at least, since the 90s Braves staffs. It starts with a (relatively) unfettered Stephen Strasburg, whom Nats brass has said they'd like to see throw 200 IP. If he does, he's my favorite for NL Cy. I think the shutdown last year is going to motivate the young man beyond belief to say "Shut this down!". I am super excited to see him pitch this year. At #2 you have last year's #3 finisher in the 2012 NL Cy race in Gio Gonzales who won 21 with a sub-3.00 ERA, Jordan Zimmermann who got really bad run support and finished 12-8 with a sub-3.00 ERA. Ross Detwiler at #4, last year was the hardest starter for leftys to hit in the majors, and finished with a sub 3.50 ERA. And their number 5 starter (how many team's would he be #2 on?) is Dan Haren, who has spent the last 5 years or so on the fringes of the Cy Young race himself. He is one of those factors that could decide just how good this rotation is. He was injured last season, but still put up Perfectly Respectable Stats for a major league pitcher, yet a step or two below the norm for him. If he reverts back (or forward, if you will) to his career norms, he becomes essentially another Ace on a rotation chock full of them.
Then there is the bullpen. They have three of the top 12 or so closers in baseball in Soriano, Storen, and Clippard. They have the ability to turn close games into 6 inning affairs when they are all on their games. Beyond that, they return Mattheus and Stammen who were integral parts of their 'pen last year. They brought in Bray as a lefty specialist, as he has been one of the better lefty specialists in baseball over the past few years. They also have Christian Garcia, who was lights out last year out of the pen but I believe will start this season in AAA working on being a starter. He has electric stuff.
This team also has major league bats on the bench in Lombardozzi and Tyler Moore, and I think Chad Tracy is returning as well. Wilson Ramos will start the season on the bench as (probably) the best back-up catcher in baseball, though he and Suzuki may switch places by season's end. Ramos is the future of the position in DC.
And then they have Davey Johnson, reigning NL Manager of the Year. No weaknesses on the bench either, as Davey should solidify what has been a HoF-caliber career in baseball.
In short, I expect this team to once again have baseball's best record (in a loaded NL... see also Braves, Dodgers, Reds, Giants... and don't forget Philly). I expect the bullpen not to implode due mostly to fatigue in the post-season this time (plus having Stras to start some of the games). I expect them to go to, and win, the first World Series title in DC since Walter Johnson in the 20s. And cement Davey Johnson's HoF credentials.