good start. Tree shadows need the be more pronounced. I know i am probably sounding like the broken record, but the zenith light system (http://www.renderring.com/zenith.zip) is ideal for this type of daylight scene. For the "too bryce-ish" sign you have, i suggest making ita terrainwith a very light displacement, or else make the bump map and specularity stronger on the square. For the tree back there, more leaves, smaller leaves, more branches/segment and no ambience.