The 2008 Marlins had won a surprising 84 games, which gave them a winning record for the first time in three seasons and was their highest total since the 2003 World Series team won 91 games. Nevertheless, management was looking to cut costs where possible. With Willingham and Olsen both set to be arbitration-eligible for the first time in their careers, they made for ideal trade candidates, and Florida found a willing partner in the Nationals, who were fresh off a major league-worst 59-102 season in the first year of their new ballpark and thus were looking to rebuild quickly. President of Baseball Operations Larry Beinfest spun the deal partially as Florida trying to return to a team based on speed and pitching, but didn't deny the financial element of the trade either.
Willingham showed solid pop throughout his time with the Marlins, hitting 26 home runs in his initial season as a regular in 2006 and slugging a combined .477 in his three starting years with the team, though he was limited to 102 games in his final season in 2008 due to injury. Willingham has remained essentially the same player throughout his career, albeit with an increase in power through his early 30's; after hitting 24 home runs in his first season in Washington, he hit a career-high 29 in 2011 after being traded to Oakland and then improved that mark with the best season of his career in 2012. In that season, his first after signing a three-year deal with the Twins, Willingham hit 35 home runs, and his slash line of .260/.366/.524 gave him his best slugging and OPS marks of his time in the majors. Willingham played in just 111 games this past season due to a knee injury that required surgery and was considered a possible trade candidate due to Minnesota's struggles, though nothing came to fruition. Willingham will turn 35 before the 2014 season and it seems likely that decline is right around the corner, but Willingham managed to put together a nice run in the time since leaving Florida.
Olsen was a top-50 prospect who showed great promise as a lefty starter in his first full season in the majors at the age of 22 in 2006. He accrued a 4.04 ERA in 31 starts and his 166 strikeouts set a Marlins rookie record. He and fellow rookie pitchers Josh Johnson, Anibal Sanchez and Ricky Nolasco all won at least 10 games, the first time in MLB history a team accomplished said feat. But Olsen regressed badly in 2007 and became a source of controversy as well, getting into confrontations with opponents and even teammates; he was also arrested during the season for allegedly driving under the influence, resisting arrest and evading police. Olsen bounced back performance-wise and behavior-wise in 2008, but he became beset with shoulder troubles after the trade and required surgery to repair a torn labrum in 2009. He hasn't pitched in the majors since 2010, and after signing deals with teams before each of the last three seasons, he was cut before each year ended; he did not pitch at all this past season after signing a deal with the Rangers about a year ago. It appears Olsen's career may be over.
As for the players the Marlins got back, 20-year-old pitcher P.J. Dean never pitched again after the trade and is out of baseball. Jake Smolinski, a 19-year-old infielder at the time, has progressed steadily through the minor leagues as an outfielder despite injury issues. A bit of a comeback year in 2012 put him back on the map as a potential future big leaguer, and he reached AAA for the first time last season at the age of 24. Bonifacio became a full-time starter for the first time in 2009 with the Marlins, who slotted him at third base; he got on base at just a .303 clip but showed his speed when he did, stealing 21 bases. Bonifacio's best season came in 2011, when he put up a line of .296/.360/.393 and stole 40 bases while playing at shortstop, third base and all over the outfield. He was limited to just 64 games in 2012, though, due to injury, and the Marlins included him in the Jose Reyes/Josh Johnson/Mark Buehrle/John Buck trade with the Blue Jays. It didn't take long for Bonifacio to fall out of favor in Toronto, as the Jays traded him to Kansas City in August.