So, for instance, if we wanted to make a new human figure and garner support dfor it, we'd have to make the Poser 7 figures?

That's an idea. Seriously. Especially if Poser 7 and D|S part ways with different weight-based rigging systems. DAZ is not doing a particularly good job of supporting Poser 5 and 6, and I doubt they'll support Poser 7 any better.

If you can't make the Poser 7 figures, perhaps the Zygote open source figures would be good ones to support. DAZ is giving away V3, M3, and Aiko, after all. And part of the appeal of the DAZ figures is all the freebies they have. When the competition is free, cheap may not cut it. At least at first.

I know of more than one merchant lately that has posted some concept renders to attempt to gauge the market for the product interest.
Maybe potential buyers would like to see more??

I'm sure they would, but I have serious doubts about that being an accurate gauge of customer interest. People often say they would buy something, then don't. Even with concept renders.