I can say finally it: “Habemus 3D on VirtualBox”. It has been hard, but the satisfaction is still greater. These integrations regarding post the precedence:

• Service of net nat of virtual the machine, interface host (does not work, and they are not still successful to understand of the reason);
• to qualify door 6000 for the X forwarding on the machine host, in mine ubuntu in the /etc/gdm/gdm.conf rows:
  #DisallowTCP=true (to comment this line);
  DisallowTCP=false (to insert this other);
• in the machine guest to type in the shell: xhost local: (servants in order to qualify the X connection to all the local customers).

Here made! Beautiful glxinfo volilà ET:

Update 8/02/2008:

To install sux (I sudo apt-get install sux);
in the shell to type sux, to introduce the password and to enter in root (avoids a xlib thus error had to the fact that is attempted to approach from root to one serveur X of one other user);

At last here a screenshot of the root of kde4 in virtualbox with 3D qualified:

and of the desktop kde4 with the transparencies:

It marks it near: