My NFC West colleague Mike Sando put together a chart that confirms in quantitative fashion what you might have realized intuitively. The Minnesota Vikings and Green Bay Packers, two of the NFL's better teams last season, have to this point retained the vast majority of players with whom they finished the 2009 season.
Much can change between now and September, but the analysis is especially relevant when compared to the rest of the league. The Vikings' 94.4 percent retention rate is the league's highest, while the Packers' rate of 87.3 ranks fourth.
According to my records, the only players Minnesota hasn't brought back is running back Chester Taylor, cornerback Karl Paymah and offensive lineman Artis Hicks. The Packers' list includes punter Jeremy Kapinos, running back Ahman Green, safety Matt Giordano and defensive end Mike Montgomery. (The Packers' percentage is lower because they had a larger base of players when taking into account those on injured reserve.)