He attended, but did not graduate from, Florida State University, instead choosing to focus on a career in entertainment in Los Angeles. He has two sons, Toshiro Lucas McWeeny, born in 2005 and Allen Miles McWeeny, born in 2008. He includes his sons in his work on the Motion/Captured blog under the subheading Film Nerd 2.0, chronicling how he introduces them to notable cinema works and individuals.
McWeeny, along with partner Scott Swan, has since become a working television writer, writing two episodes in the Masters of Horror series, both directed by John Carpenter. The pair also co-wrote the episode "Skin and Bones" for the NBC horror/suspense anthology television series Fear Itself. In May 2008 it was announced that Bat Out of Hell, a motion picture written by McWeeny and Swan, would be directed by Joe Dante. He also continues to work as a film critic, though he has been banned from Twentieth Century Fox press screenings.