This next-generation of MakeHuman is completely stand-alone – it is writen in C, not python. Once a character is made in MakeHuman, you will be able to save it in either the MakeHuman specific format or an .obj file (or both). The .obj can be imported into Blander and other “one-stop” modeling programs, to be added to a complex scene, for example, containing many other models. Additionally, you will be able to render an image of your (eventually) posable character. The image’s background is transparent. This .tif image can then be imported by many image manipulation programs and used in post production.
For example, you could model a sleigh in Blender, and render. You could then model a Claus in MH with hair and clothes (eventually) and render. You could then combine the two images in post production and end up with Santa in his sleigh. Or, you could make the sleigh in Blender, and import the MH Claus to your scene. You will be able to save your Claus made in MH with high-quality UVMaps (eventually). Eventually=sometime between now and late February 06.
Specifically regarding the Muscle Engine System, the morph targets used in your character are modified by the engine according to muscle group settings and according to the position of limbs in relation to the body. For example, if you pose your character with its elboe bent, the bicep will bulge and the tricep will relax. But, all these individual morph targets combine in the end to make the mesh of the model for renders and for saving in .obj.
Now, specifically regarding what or how much of the “posability” or “animability” (I think I just made those words up) I truly do not have a diffinitive answer for you at this time. I only know right now that posability is planned for the beta release. I know that as much of the mesh information that can be saved in .obj format, will be (eventually).
I, like you, hope that I will be able to import an MH character into Blender and not have to develop a skeleton for it, and have the muscles work right when I pose it in pose mode, as in the elboe example I described above. But, again, I just do not know at this point in time, but I will keep everyone informed as much as possible and as soon as possible.