With the Earth I can see it and even with Jupiter with its giant EYE and all that. For the Sun it can be very hard to get the detail needed out of something that looking directly at will melt your retinas. O_O It's also hard to light something that emits light. Very good effort with the sunspots to add depth. Not as effective as the clouds on the Earth, but not something I'd have though of myself.
Clever concept and after the solar system is complete it would be cool to upload them as a single sheet instead of many. Some will stand out and some will suffer by the nature of the planet (the sun is actually lame looking but when you think of the earth one it makes sense). Just a thought.
Thank you to all.
I tried to get a shading like this.
http://www.sitondesign.com/uploads/catalog/products/photos/big/p101_2.jpg
It's very difficult, also I tried to add solar prominences but looks horrible, I'm not satisfied with it, I think I could improve it, when I find a way to do that.
Edited
I added a bit of texture, now it's more detailed. :P