The World Series is finally set, and what a showdown: Red Sox vs. Dodgers -- a 108-win Boston team that was MLB's best team in the regular season against a Los Angeles squad returning to the World Series for a second straight season after falling just short in Game 7 a year ago. If we're lucky, this Fall Classic will be exactly that -- a classic. But before the World Series kicks off on Tuesday in Boston, here are five key storylines to watch.