I'm talking about Yunesky Maya, the 28-year-old Cuban who pitched alongside Aroldis Chapman in the World Baseball Classic in 2009. He's considered close to ready to starting in the big leagues, mostly as evidenced by his performance in said Classic (one earned run in 7.1 IP).
Assuming he passes a physical next week, I would think we would see him after he logs some time in the minors this year. The Nats likely want him to get some audition time this year before he competes for a rotation spot in 2011. He's not a dominant pitcher like Chapman, but he has four pitches in his arsenal and reportedly generally throws in the 88-92 MPH range.
While he's a legitimate candidate to be successful, it should be noted that he's been a free agent for over a month. While the Yankees, Red Sox, and Phillies were interested, you always have to be suspicious when the Nats win a "bidding war" (see Chien Ming Wang). Still, the Nats put out a legit bid for Chapman, and perhaps did win a bidding war for a legit MLB starter in this case.
You have to at least be encouraged by the Nats' trying. This was the 32nd international prospect the Nats have signed this year--welcome improvement since the days of Esmailyn Gonzalez.