Creative Common as open source license?

[Manuel Bastioni]

Hi.
Excuse me for my poor english.
I'm one of developers of MakeHuman project:
www.dedalo-3d.com

It's a plugin for Blender, to make 3D humans.
It's composed by some python modules, some images and one human 3D 
model. Actually it's under GPL.

However it seem GPL don't work fine for MakeHuman output:
http://projects.blender.org/forum/forum.php?thread_id=50313&forum_id=60

It's a strange case, because we try to apply GPL to a 3D model.

The 'source' of 3D model is a list of verts and faces, or the 3d file 
itself. This make some strange GPL loops (the output is a new 3D mesh, 
derived work from GPL'd 3D mesh, and so again under GPL)...and the 
problem is the professional user don't want release the models (source) 
of their works.

Normally a software under GPL can make commercial output (I can make a 
image with Gimp and distribute it not GPL'd), but not in MH case.


After the long discussion in the forum above, we have decided to use, 
for 3d model, this creative common:

http://creativecommons.org/licenses/by/2.0/

we think, because the source of 3D model is the 3d file itself, this can 
be considered, in this specific case, an opensource license.

Infact, the source (3d file) can be
"""
     *  to copy, distribute, display, and perform the work
     * to make derivative works
     * to make commercial use of the work
"""

The only restriction is that any artist should specify that is "made by 
MakeHuman"

Now my question.
The python code will remain under GPL
The 3D model under the creative common.

Actually We have the OSI certified on dedalo-3d.com.
We should remove it :-(
??
Or the CC in this specific case can be approved as OpenSource license?

thx,

              Manuel