Rod Stewart is kicking things into high gear. The rocker is on the second leg of his tour with Stevie Nicks and will play a residency at Caesars Palace in Las Vegas through October. He’s also working on a Christmas album, according to a source, which will be produced by David Foster and feature three duets, including one by Grammy winner Michael Bublé. There’s also word Stewart is planning a studio album of new songs, produced by Foster and T Bone Burnett. His rep had no comment.