"I'm leaving to focus more time and energy on my novels and other non-video game related projects," Karpyshyn wrote in a blog post on his personal site. Though he won't say where he's going just yet (if anywhere), he promised continued work on an upcoming SWTOR companion novel (like his work on the Mass Effect books).
To help assuage concerns about BioWare's writing post-Karpyshyn, he points out that, "The story and dialog in any BioWare game is the result of an entire team of writers working together, and I often felt I received an excessive amount of the credit for the games we created." He cites Mass Effect 3 and Dragon Age 2 as proof that "BioWare can get along just fine without me." And though he apologizes to those who will miss his work in the gaming world, he promises that he'll finally put the finishing on his own "original fantasy series," should you wish to keep up with his fantastical worlds.