This awesome looking controller from Denon is being released December 1st. As far as Traktor Pro goes, this is probably the one controller top two controllers suited for the layout, though it's got some extra controller functions that are more geared towards Digital DJ. The S4 controller is made for the S4 software, but can also be used in MIDI mode and send MIDI signals to Traktor Pro. In my opinion this controller would be just as suited for Traktor Pro as the Kontrol S4.
Denon has always delivered high end products for the last 20 years. I guess this controller is no exception.
It is made to be mounted in a 19" rack and is suited for the dark nightclub environments with it's very good lighting distributions.
My conclusion will be that if you are looking for a four deck controller for Traktor Pro. I would have to try this controller before I chose a controller, but it would still be a tough choice between the S4 and the DN-MC6000.