This is a blend file that allows you to get planets rendered within a minute ! Although it is Internal and Cycles compatible, you get best results on Cycles. You can use it by linking the objects (Planet.Ground, Planet.Clouds, Planet.Atmosphere) and/or the NodeGroups (all of them), and just edit the material nodes to replace the textures. Night mode not (yet) supported, looking for a working method on Cycles.
With the last (2.1) update, you can define the amount of "atmospheric scattering" effect will be applied to the atmosphere shader (Cycles only). Plus, you can now use both normal and bump maps for ground and clouds textures.
The "Planet.Night" has to be rendered on a separate layer. The Day/Night selector node group will then determine where to show the cities' lights based on the diffuse power (pass has to be activated in the Planet layer)
[Video tutorial link upcoming]
For some reason I can't download it. Looks like there is no file being downloaded... But I am really curious about this material, does it uses image textures or is it entirely procedural?
great