By Mark Lamport-Stokes (Reuters) - This week's PGA Championship in Louisville, Kentucky is likely to deliver further confirmation that a new world order is establishing itself in the game with players such as Rory McIlroy and Adam Scott now leading the way. While Tiger Woods, Phil Mickelson, Ernie Els and Vijay Singh have been golf's dominant figures over the past two decades, the present and immediate future appears to belong to McIlroy, Scott, Bubba Watson, Martin Kaymer and other 'young guns'. Masters champion Watson and U.S. Open winner Kaymer have each won two majors while in-form McIlroy, who clinched his third at the British Open last month in wire-to-wire fashion, will be aiming for a career grand slam at next year's Masters. As Scott prepares for the year's final major, the PGA Championship at Valhalla Golf Club beginning on Thursday, he is well aware of a gradual 'changing of the guard' at the game's highest level. More...