Comment 18 for bug 1212821

I've been bitten by this also on a new install, exhibiting exactly the same blank desktop with no icons, side launcher or top panel.

My gfx hardware is an Intel 855GM (not an 865 but is of the same generation chipset).

The OpenGL failure (Root visual is not a GL visual) and the resulting compiz opengl plugin failure is due to the intel driver defaulting to the new 'sna' (Sandybridge) renderer.

This generation of intel gfx cards needs the old 'uxa' renderer and so needs to be manually set in xorg.conf.d entry like so:

# cat /etc/X11/xorg.conf.d/20-intel.conf
Section "Device"
   Identifier "Intel Graphics"
   Driver "intel"
   Option "AccelMethod" "uxa"
EndSection

That should give you a very slow but working software rendered Unity desktop.
It's debatable, but this slow desktop performance is probably unacceptable for everyday use.

The card only supports up to OpenGL-1.3 and Unity3D needs OpenGL-1.4+ which is why it falls back to software render.