Will Ferrell step on up. The guy told me he saw this year’s “Elf” as a bit of a left turn…what the heck do you call a Woody Allen film? The “Old School” star has replaced Robert Downey Jr on the unconventional director’s next film. Also joining the cast are Amanda Peet, Brooke Smith, Zak Orth [go bud!], Wallace Shawn, Gene Saks and Vinessa Shaw. Previously cast were Radha Mitchell, Chloe Sevigny and Jonny Lee Miller. In addition, The Hollywood Reporter adds Jason Biggs to the role call. Production is scheduled to begin Sept. 22 in Gotham and wrap in November.