The article mentions a potential application using lenses with incredible properties. Could one use these materials to make a lens that focuses x-rays? It has been postulated for decades that if one could use an x-ray light source for microscopy, it would be possible to observe the machinery of cells in real time (assuming the energy doesn't obliterate the cell). My understanding is that it isn't possible to make a lens to focus an x-ray as you can with visible light or using magnetic fields for electron microscopes. If these materials allowed this, it would usher in an incredible era of biological understanding.
No, the problem with x-rays is not the lens shape, but rather finding a material that will refract (i.e. bend) x-rays. X-rays tend to just go right though, or be blocked. It's hard to find something where the x-rays slow down, but keep going.
Also, the higher the frequency the harder it is to make a meta-material that works for it. (Since the feature sizes need to be about the same size as a wavelength.) We're barely there for visible light, x-rays are completely out of reach.
I am speaking way over my head - I did work with researchers doing optical metamaterial work one summer as an undergrad, but my knowledge is very naive - but one of the main draws of superlens (hyperlens was the term that I was familiar with) is that you could magnify past the "diffraction limit" on a live sample.
