Hi Esh.
It was actually DNJ who posted something the back end of 2005 about this. I only remembered when I saw the picture posted by yourself of this set up

Here's Donny's post
http://www.synthzone.com/ubbs/Forum37/HTML/012417.html

I also thought Abacus posted something about TMS but can't find it.

As soon as Yamaha post some more info or pictures I'll do a link to them, unless someone get's there first. I do know that they are catering for the organist as well with an extra manual. Suppose it's similar to what Wersi do with their stuff. They have the Abacus and Ikarus keyboards, they did an Abacus pro (2 manual) Xenios with 2 manuals then the all butt kicking organs that cost an arm and a leg.
If Yamaha keep the cost down they could be onto a real winner here.