I created this render (12 hours 20 minutes) by loading bmp heightmap (1600*1200 resolution 300 bpi B&W) from a fractal generated by ultrafractal.
Applied njen's aurora and changed the sun direction.
Filled the mandelbroth basin with lake, and applied some coloring layers.
Downsized from 1600*1200.
http://img336.imageshack.us/img336/2412/mandel2ic2.jpg
That are some unusual colors xD Background mountains look a bit dull, and try to add a max slope for the white color,that'll make it more complex :) water + foreground are very nice!
I think a little more variation on the textures would help, as well as maybe a darker sky to accentuate the aurora.
I like the general setting and some of the lighting is really creative. The ground needs some work.