OS X doesn't support OpenGL 4!
Here's something that I discovered accidentally: OS X doesn't support OpenGL 4! All you get is 3.2, which was recently supported through Lion. WTF Apple?!? Support for the latest OpenGL version supported on your GPU is something you take for granted on any other OS. I don't think Apple even sells a computer that doesn't have an OpenGL 4.0 capable GPU, so there's really no excuse for this. I was looking forward to getting a new MacBook Pro or Air and playing around with the tessellation shaders and writeable memory buffers, but that will only be possible if running Windows or Linux on it.