Dave Grohl is thisclose to finishing a new Foo Fighters album. “It’s the record that we’ve threatened to make for a long time,” he says. “We’re finally doing something that’s surprising even us.” But on Thursday afternoon, Grohl is 100% focused on late Pantera guitarist Dimebag Darrell Abbott, who is being honored that night at the eleventh annual Dimebash at the Observatory in Anaheim, just down the road from NAMM. (Abbott was shot to death by a fan during a show in Cleveland in 2004.)