fangraphs had a report on players' prime years. Can't remember the specifics, but their conclusion was that, basically, pitchers should come up as soon as they are even close to being ready. Prime years were something like 21-27. For hitters, it was actually older, more like 24-30. The super-2 thing is not an issue, but Kenny may be very closely looking at the value Viciedo may have in 2011, and thinking why waste a year toward free agency, when he may just be getting in his prime then.