Terragen 2 with its better reay tracing engine is out yay!
just have a look at what the new render engine can do
http://www.planetside.co.uk/images/stories/planetside/seth-promenade_2_exret.jpg
Top Changes
Ray trace objects for faster, higher quality rendering of objects and populations
Reduced render time and multithreading enhancements
Population and object rendering fixes
Black triangle fix
New shaders
New populator features
UI improvements and fixes
Safe saving fixes/changes
Windows drag-and-drop and file association fixes