Next week, Who Wants to Be a Millionaire host Regis Philbin will award one gutsy contestant over $2 million the biggest individual payoff in quiz-show history. (The show's bonus pool is brimming with cash because nobody's won the top $1 million prize since 24-year-old Maryland native David Goodman's triumph on Jan. 4.) Adding to the week's unprecedented thrills, yet another player will snag a cool million. And in other Millionaire news, beginning Saturday, visitors to Disney World in Orlando, Fla., can sit in "the hot seat" at the theme park's newest attraction a replica of the quiz-show's set. Unfortunately, they can't play for cash, just parting gifts.