The Washington Nationals, despite the media linking them to almost every high-dollar free agent, have had a somewhat quiet winter. As such, it's tempting to dismiss them. After all, an 80-win team whose primary offseason signing is a Type-B free agent (Edwin Jackson) isn't redolent of "contender." In the Nats' case, however, that's precisely what they are: a contender.
To be sure, the Nats can't be considered a favorite for a playoff berth, in part because they have the misfortune of playing in a division in which only one team -- the Mets -- can be brushed aside as a non-factor. But they're in the fray, which is more than can be said for their status in recent franchise history.
In 2011, the Nationals, as mentioned, notched 80 wins. However, their team WAR totals (i.e., hitting and fielding WAR totals for position players + WAR for pitchers + the 43.0 WAR that constitutes the replacement-level team) show they have the underlying indicators of a "true" 77-win team. That means their foundation for 2012 might be a little shakier than you might think.
That said, the Nats are to be taken seriously, and their rotation depth has much to do with it. After all, Washington had a fairly enviable starting five even before adding the underrated Jackson and Gio Gonzalez (via trade).