Alex Ovechkin is a hockey megastar but hasn't been huge on Madison Avenue. That could change now that the Capitals left wing has signed with IMG Worldwide, one of the top sports agencies in the world. Think commercials with Tiger Woods. Or appearances with Peyton Manning. There's good reason to believe he could become the biggest mainstream star the NHL has seen in 20 years. Ovechkin enjoys the spotlight, but this is not a case of an athlete begging to find the agency that will brin...