Ok here's the deal with the Arroyo for Pena deal: This isn't a one year deal, this is for the future. Wily Mo is 24 years old and has tons of power (something the Sox farm system lacks which is power from the OF). With Wily Mo the Sox have a right handed bat off the bench and a platoon with Nixon who can't hit lefties to save his life. Also with Wily Mo, the Sox don't have to waste money to resign Nixon as they have his replacement on the team now. Also considering Pena's age he could also take over for Manny Ramirez when he retires.
Arroyo is putting up great numbers this year no doubt but he's also playing in a weaking league and division. The NL is a joke, if he was in the AL he'd probably be 6 and 6 with an ERA over 4.00, no one would be making a stink about it. If Arroyo wasn't doing well no one would care either. Arroyo is nothing more than a 3rd starter if best don't let those NL numbers fool you. Also people forget that when Coco Crisp and Nixon were injured, Wily Mo CARRIED the Sox offense because neither Manny or Ortiz were hitting around that time. Wily Mo in 112 at bats had 4 home runs, 18 RBIs, 12 runs scored with a BA of .321 and an OBP of .370. Those are pretty good numbers until he got hurt.
I loved Arroyo as much as the next Sox fan but I can't say that this trade is horrible. Sure it hurts the Sox a little when we have guys like Jason Johnson, David Pauley, Lenny DiNardo and Kyle Synder pitching as a 5th starter but I'm not even sure if Arroyo would be in the rotation if everyone was healthy (Clement and Wells) and even if Lester was up and one of those guys were healthy.