Meh, making sprites like that in creative mode is too easy. It's just a matter of finding a sprite online and plopping down blocks of the right color in the right places based on that sprite. As long as you have some time to waste, anyone could make something like that.
The 3D ones at least took some skill, I guess.
Sorry, I didn't mean to sound so negative.
Notch is adding weather in the next patch, by the way.