Keith Law thinks the Nats did alright:
----------------
The Washington Nationals, Oakland Athletics and Seattle Mariners pulled off a three-team deal Wednesday evening, which featured Michael Morse heading to Seattle, John Jaso going to Oakland, and pitching prospects A.J. Cole, Blake Treinen and a player to be named moving to Washington.
The Nats came out way ahead, the A's made a modest gain, and the M's leave me scratching my head at why they'd ask for change for a five-dollar bill and be happy with three singles.
The Nationals move a player for whom they had no use, and to whom they would have paid $6.75 million just to sit on the bench. The acquisition of Denard Span earlier this winter plus the re-signing of Adam LaRoche put the oft-injured, twice-suspended-for-PEDs Morse on the outside looking in, with one year left until he was due to hit free agency.
For one year of Morse's services, they reacquired right-handers Cole and Treinen, as well as a player to be named. Cole started the year in the high Class A California League and was so bad that the A's demoted him to the low Class A Midwest League, which he dominated for the second year in a row; he struggled with his arm slot earlier in the year, dropping down and losing some velocity as a result, but was better in the second half.
Treinen has a live arm but has some history of injuries dating back to his days at South Dakota State, and probably projects better in the bullpen given the lack of life on his fastball. He did finish in relief in high-A after scuffling as a starter earlier in 2012, throwing more than enough strikes but giving up too much hard contact. The Nats' farm system was nearly wiped out after a series of trades, a couple of promotions, and a 2012 draft that put most of the team's eggs in one (very good) basket, so this is a nice depth-building move for a player who didn't fit their roster any longer.
(Incidentally, readers asked for my thoughts on their deal with Rafael Soriano; he's a very good short reliever, but $14 million for a reliever who's never been worth more than 2 WAR and probably can't hold up for 70 innings a year is way too steep. I also wouldn't give up the 31st overall pick, as the Nats did, to sign a reliever, especially since their pen was already a strength. But Soriano is pretty low-risk as relievers go, at least in terms of performance on the field.)
-------------
The rest of the article says the A's did alright and that the Mariners made a horrible deal (gave up three years of Jaso for one season of Morse).