<p>I would advise against buying a laptop with a powerful GPU just for an undergraduate graphics course that you may or may not take. I support the other comments that suggest Linux (Ubuntu is especially popular these days, and very easy to get started with).</p>
<p>Just to clear some things up that others have mentioned here, if you want to speed up ray tracing and “rendering frames” in a program like 3DSMax/Maya/Blender you will want a powerful CPU, not GPU. The graphics cards are usually only used in real-time rendering (as opposed to offline rendering used for rendering films). Utilizing GPUs for general purpose computing is starting to become popular, though, and CUDA/OpenCL is starting to take off in the sciences.</p>
<p>A better GPU is useful for previewing geometry inside of an animation program and programs written in OpenGL / Direct3D (calling it DirectX is slightly incorrect). For an undergraduate graphics course, you will probably stick to OpenGL with simple programs.</p>