From sports illustrated:
The Packers trade with New England in order to get back up into the first round and get an outside linebacker to play opposite Aaron Kampman in Dom Capers' new 3-4 defense. The addition of Matthews and B.J. Raji gives the Pack two projected starters to inject into a defense that took a significant step back in 2008. Packers GM Ted Thompson gave up a lot with three picks in rounds two and three, but it will be worth it if Matthews continues the meteoric progression of his career, which started as a walk-on at USC.