Zeiss has no plans to bring back the ZK mount for Pentax DSLR cameras
According to Pentaxrumors, Zeiss has no plans to bring back the Pentax ZK mount for Pentax DSLR cameras despite the recent introduction of the K-1. They have discontinued their ZK type lenses in 2011 because the request was too low. They do not plan to offer K-mount lenses again within the next future. If Pentax reaches a similar market share among the full frame bodies like Canon and Nikon, they will reconsider it.
via: Pentaxrumors