Here's a summer's-day stunner: Matt Kenseth, the Sprint Cup points leader and current best average finisher, is leaving Roush Fenway at the end of the 2012 season. His replacement will be Ricky Stenhouse Jr., the reigning Nationwide series champion and a driver well positioned to make the jump to Sprint Cup. The Roush Fenway statement announcing Kenseth's departure was long on gratitude — "We're fortunate that we were able to tap into Matt's potential and bring him on board many years ago," said Jack Roush — but short on the specifics of whether Kenseth jumped or was pushed out of...