|Strasburg in his warmups. Get used to it.|
As of right now, I don't think any team has officially clinched a playoff spot, but let's avoid the silliness for a second. The Nats currently have the best record in baseball, have a 5 game lead in the division, and if, for some reason, they were to flummox themselves away from such a lead, they would still have a pretty significant lead in the wild card race. That Nationals are going to play at least one post-season game, and probably more than that.
So they've gone out and won more games than anybody else to this point in the year, so they must be the favorites at this point, right? Well, not exactly. They've allowed just 525 runs, which is the best in baseball, but have done so with Stephen Strasburg taking the mound every fifth day. Strasburg is obviously shut down for the rest of the year, so don't look his way. They've also had the pleasure of playing in the NL East, where Philadelphia, NYM and Miami have gone out and disappointed everybody at one point or another.
They've still got a nice rotation even without Strasburg-- Gio Gonzalez is a Cy Young candidate, and Jordan Zimmermann, Edwin Jackson and Ross Detwiler have all been quite good all year long-- and the bullpen has been more or less excellent all year long, so the rest of the pitching staff should still be plenty able to pick the extra slack down the stretch and in to the postseason.
Despite cooling down a bit recently, the offense is still really good. Danny Espinosa has had a fantastic year to this point, Ryan Zimmerman has been ridiculous since the all-star break, and Bryce Harper has put up 4 WAR as a 19-year-old. Believe the hype, children. Beyond that, Adam Laroche suddenly doesn't suck anymore, and Jayson Werth is back to hitting like Jayson Werth (though he's only played in 66 games this year due to injury), bouncing back after a rough season last year.
There weren't many people who truly believed in this team at the start of the year (myself included), but they are quite clearly deserving of their current spot at the top. This team is quite young, and Jayson Werth is the only player in the roster with any significant playoff experience, if you're the type to buy in to such a thing. Fortunately for practically everyone on this team, they're going to grow up together. Edwin Jackson is a projected free agent, but the team has control over quite literally every main piece of this club for at least one more year (Mike Morse is a 2014 FA, Werth, Zimmerman and Gonzalez are signed through '17, '17 and '16 respectively, all others are on rookie contracts or are arbitration eligible through 2015), so if experience really is an issue, they're sure to gain some over the coming years, because this team has dynasty written all over it.