Making a return to the program that played host to an infamously weird appearance back in February of 2009, Joaquin Phoenix will appear on David Letterman's Late Show Wednesday, September 22 to promote his new documentary-ish film I'm Still Here, according to a CBS press release. What to expect? Well, don't expect a mea culpa. Phoenix seems deep into I'm Still Here mode based on all the press releases we've gotten about appearance by a Joaquin Phoenix impostor making appearances at the Toronto International Film Festival, appearances in no way arranged by Phoenix's people, we're sure.