The Washington Nationals Thursday evening traded Matt Capps, their lone All-Star representitive, to the Minnesota Twins for MLB-ready catcher Wilson Ramos -- Baseball America's No. 58 overall prospect in 2010 -- and left-handed relief pitcher Joe Testa.

Ramos is a 22-year old Venezuelan and is widely considered a strong defender that will hit for gap power at the major league level.  With Triple-A Rochester this season, Ramos hit .241/.280/.345 in 295 at bats and hit .296/.321/.407 with Minnesota in 28 plate appearances when Joe Mauer was injured earlier this season.

Baseball America ranked Ramos as the Twins No. 2 prospect and Keith Law of ranked him as the No. 42 overall prospect.

From Law's Top 100:
Ramos has had trouble staying healthy, but when he plays he hits, and he plays a premium position at which bats like his are hard to find. He missed time in 2009 with a broken finger and a partially torn hamstring, which makes his .317/.341/.454 line in 54 games at Double-A even more impressive. Ramos is big, taller than his listed 6-foot height, and his large frame suggests he might outgrow the position. But right now he throws extremely well (he’s nailed 43 percent of would-be base stealers in the past two years) and his receiving is adequate. He does need to work on the intangible aspects of catching, like handling a staff, something the Twins value very highly in their catchers. At the plate, he has strong hands and very good hand-eye coordination, with a hard, line-drive-oriented swing; he’s also impatient, drawing just six walks in his abbreviated 2009 season, and will have to up his patience or hit well above .300 if he ever has to move out from behind the dish.
Testa, a 24-year-old reliever, has a career 3.33 ERA in three minor-league seasons. In 36 games between Class A and Class AA this year, he's a combined 2-5 with a 5.50 ERA.

Assessment:  This is an absolute coup for GM Mike Rizzo.  He turned a half-season of a free agent closer into a legitimate MLB-ready player at a position of need.  The situation couldn't have worked out any more perfect for the Nats.
Capps had arm trouble in 2008 and spent much of 2009 building his arm strength back up but struggled to a 5.80 ERA.  The Nats bought low on Capps, as they were the only team that assured him a shot at closing.  Once the season started, Capps performed admirably, as he's been at the top of the leader board in saves all season.
Capps parlayed that into an All-Star berth, further reinforcing his trade bona fides.  Rizzo knew that Capps would garner a HUGE raise in arbitration next season, so he sold Capps at his absolutely highest value.  Again, an absolute coup.
As for the immediate question of who closes games for the Nats this year, it's really immaterial.  The Nats will want Drew Storen in that spot quickly, but manager Jim Riggleman has a penchant for veterans in key spots (Willie Harris, anyone), so it wouldn't surprise me to see Joel Peralta and Tyler Clippard getting some opportunities as well.
As for long-range projections for Ramos, I think this move confirms the suspicions that the team has concerns that Jesus Flores may never make it back from his shoulder injuries.  As well, Derek Norris could be moved to first base to get him from behind the plate and into a slot where his bat can get him to the bigs faster. 
Regardless, it gives the organization another very well-respected prospect in a position of high demand and volitility.