Joaquin: Junkie or New Borat?

The case of Joaquin Phoenix gets curiouser and curiouser following the actor' shambolic appearance on the David Letterman show. The odd tics and nodding-off behavior that drew Letterman's scathing wrath are typical of a heroin user, Gawker points out. But many speculate that it's all a Borat-like hoax act by the thespian who insists he has sworn off acting for a laughable rap career. Complicating the issue is Casey Aflleck's documentary (mockumentary?) on the actor's career "transition."
(More David Letterman stories.)