The screenshots certainly look like the officiallly released concept artwork. The fan site claims they have received the screenshots from an "anonymous, but reliable source." In fact the site claims the screenshots were submitted by Interplay to prove that work on the Fallout MMO game is underway in their current court fight with Fallout's owners Bethesda Softworks.
Gallery: (Possible) Project V13 Screenshots
Gallery: Project V13 Concept Art