Hi,
I know you can use the models in commercial applications and sell those applications. You can even make images from the models (i.e. advertising pics, etc.) and sell those. But, can you make a morph and then sell the model? Don't think so. It's not exactly a derivative work, it's not exactly your work (other than moving a few sliders and hitting export).
On Turbosquid, someone appears to have posted a model for sale that looks extremely, extremely similar to a MakeHuman model. The link to this model is http://www.turbosquid.com/3d-models/hum ... obj/470681. I submitted a ticket to them, but they are having trouble making the connection. Maybe the team here wants to make contact with them if this sort of thing is not allowed (which I don't think it is). They need screenshots of the same work inside the tool, I believe.
It has already sold at least one copy. I say that because it has a review listed below it, and you have to buy it to review it.