No reason to get all excited about the discovery that one or more of the Stonehenge bluestones came from Pont Saeson or somewhere near it. After all, there are more than 30 different stone types represented at Stonehenge -- and every new piece of geology seems to suggest additional stone sources. As Judd suggested a very long time ago, this simply looks like a collection of glacial erratics. Pont Saeson, Carn Goedog, Carn Alw, Carn Llwyn, Carn Clust-y-ci and other sites on the northern slopes of Preseli are exactly the sort of places where you would expect glacial entrainment to occur, with ice coming in from the NW and flowing towards the SE. I think more locations will be found in that general area as the geology work by Rob Ixer and others proceeds.