To be honest you can pick up all their old albums for under a fiver now anyway so just go buy them all (if you don't already own them). The whole collection is worth having. The first two albums are out of this world good, the next is an amazing listen, the fourth... well it's rubbish but has a couple of great tracks, the fifth is rock at its best and this, their sixth, is stunning.
I think there were previous talks about the Stereophonics bringing out their first Greatest Hits album but it doesn't seem to have happened. But take my advice, don't wait for a Greatest Hits album. There is one coming out in November called "Decade in the Sun", and it will feature two or three new songs. But it's well worth getting all the albums, including this one, and simply just downloading any new songs.