What about we use this thread to gather up all knowledge we have about the GE so far? As for terrain purposes that is. Here is what I know:
Fog and effects related to it (coloring/lighting) can be edited with the Lighting Editor found under the Windows tab, as OffGraphic said.
For my part these "weather" doodads doesnt work, they simply doesnt show up, if anyone know what is causing this, then please, do tell.
You rise and lower a doodad in the terrain by hitting Page Up and Page Down, not like before when you had to hold CTRL to do this, this also confused me when I started using the editor, How do I make a doodad larger and smaller? Well, thanks to FrIkY I solved this problem

<3
You use + and - to make a doodad larger and smaller, there are no longer a horizonal and vertical enlarger and en"smaller?" which, I dont know if is TOO good.
You can also use / and * to make your model shift 90 degrees FROM SET ANGLE, all around. Hard to explain, try it and you'll understand.
Other than this I dont know if there is too much new that have changed. I am disappointed at the lack of a simple way to turn doodads with hotkeys, but there might be a way, just I dont know yet
If anyone know anything else that concerns terraining that they find important to share, DO SO!
