You won't have to learn a 3d program, but you may have to learn a bit about POV-RAY programming...
http://www.matwei.de/doku.php?id=en:eagle3d:eagle3d
Eagle 3d is essentially a ULP that will generate the POV-RAY file. You then run the pov file through povray and it will generate the 3d render for you.
It has over 1000 parts, mostly generic looking, but more than sufficient to see what the board will look like.
You can also create your own parts if you are handy with a modeler and hacking the povray code... I am not 