I set up the diffuse material, add a image texture node, select the image and yet everything remains beige. Any ideas? The tutorial I was following along it worked just fine when he did it... but he was using v2.6x
You probably didn't add a uvmap. A UV map is what maps the 3d coordinates of the object to the 2d coordinates of the Image being used as a texture.
Notice properties -> Data -> UV Maps has no entries.
The simplest way to see a texture there is to press the + symbol to the right. Your viewport rendering will show a texture on the Cube.
See blender's manual page about uv_mapping.