Even though Justin Bieber these days might be a bigger deal than global warming, An Inconvenient Truth director Davis Guggenheim has dropped out of directing the young singer’s 3D concert film for Paramount Pictures. Guggenheim withdrew last night. I’m being told  from all sides that Guggenheim decided he’ll be too busy promoting Waiting For Superman, which Paramount acquired right before Sundance. But I wonder if Guggenheim might have gotten too much razzing from all of his documentary peers who did spit takes when Deadline revealed Guggenheim was signing on. Paramount has begun interviewing directors for what is being viewed as a good gig, because Bieber has such a fervent following.