He has some of the most average career numbers imaginable: 106-106, 4.02 ERA
But, his 2009 season has been very good: 8-6, 2.64 ERA. (His ERA is 5th best in baseball among starters and 1st among left-handed starters).
They had to give up Luke French, a young left-handed starter, and Mauricio Robles. French performed well with the Tigers and Robles is supposed to be good too. Washburn will be a free-agent at the end of the season.
Any time the Detroit Tigers trade a young pitcher for a veteran pitcher to help them in a playoff run, everyone immediately thinks of John Smoltz and how they traded him to the Braves for Doyle Alexander in 1987. Alexander went 9-0 for the Tigers down the stretch and helped them win the division. Smoltz went to the Braves and won 210 games, saved 154 games and went 15-4 in the postseason on his probable way to Cooperstown.
If that happens again, it will hant them for a long time. Still, they can't make decisions based on what happened more than 20 years ago. They have a good shot at making the playoffs, but it will be tough. They're not going to score a lot of runs, but they can win with good pitching and decent offense. For this plan to work, Polanco and Guillen need to hit well for the rest of the season.