According to BioWare sources, Karpyshyn was secretly working on a screenplay for a Star Wars: Knights of the Old Republic . Lucasfilm is developing this feature film as on as one of their planned Star Wars spin-off movies.
Karpyshyn's works of video game writing are as follows: Mass Effect, Mass Effect 2, Jade Empire, Baldur's Gate, Neverwinter Nights, and both Star Wars: Knights of the Old Republic and Star Wars: The Old Republic.
It seems not true of the KOTOR movie rumors. According to latest report in AICN, Karpyshyn confirmed that he knew nothing about the movie Knights of the Old Republic. It could be possible that he was working on it but had to keep a secret. In my opinion, it seems a rumor and not worth our attention. Karpyshyn’s old colleague at BioWare really hoped him to do this, but it could be just a rumor. We should shift our attention to other things.