This image is basically just a test to see how realistic clouds I could render with Blender 2.5 volumetric materials. Saw that the results were pretty nice so I decided to make it into a "real image".
Clouds generated from a plane shaped the way I wanted the clouds in the final image. Used a lot of fractal noise distorting on material to create that natural look. Volumetric material was originally pretty dark so I used 3 sun lamps to brighten things up. Rendered out of Blender 2.56a and then brought it to Adobe After Effects CS4. Used a VideoCopilot AE plugin Optical Flares (which by the way is awesome, just too bad there isn't a PS version...) to create the huge flare for the sun. Also did color correction stuff in AE...
Took under an hour to make... (time spent mostly waiting for Blender to render