Two months ago Samyang asked on their Facebook page "Which new Samyang lenses, you like to see in Samyang family" and then commented about a fast 135mm or a tilt-shift lens:
I personally would be interested in a cheap tilt-shift lens solution - there is no need for autofocus and if Samyang can come up with an acceptable IQ, this could be an interesting alternative to the $2000 tilt-shift lenses from Nikon and will probably be available for other mounts as well.