As usual, the news article is maddeningly short on details, but I assume they're going to be using this for interferometry between all those radio telescopes -- combining the signals with some really heavy DSP to get a relatively high-resolution raster image of a portion of the sky.
I agree with the assumption of this projects application though I find it maddening that they're choosing to look 'up' instead of _down_.
I believe more practical value can be obtained if that enormous computing resource were used to investigate the smallest components of the cosmos.
Take Test4Theory[1] for example whose stated goal is to help in refining the accuracy of the Standard Model of Particle Physics; this would create the ability for us to derive a more accurate understanding of Nature and would exponentiate our development of technologies that are key to our species survival.
http://en.wikipedia.org/wiki/Astronomical_interferometer
http://en.wikipedia.org/wiki/Square_Kilometre_Array