Camera bits should all be there in nemo. The only missing part AFAICT is a GStreamer sink for wayland. gstwaylandsink could be used. I haven't tried it myself.

Someone can try something like this:
gst-launch subdevsrc2 ! ffmpegcolorconv ! waylandsink

And see if you can get any picture.

Anyway, this is not sailfish specific but sailfish camera app most likely will not run on n9,