I now finished my project on creating a 3d rendering of a stylish earth both for animation and still images. This was inspired by a major German broadcast network using such graphics in a similar fashion.
A short intro video on a potential use case can be found on vimeo:
The set up of the blend file is quite simple. I use an equidistant cylindrical projection texture of the earth taken from a spec map and transformed into a black and white high resolution texture to control the materials. In the material setting I use this to mix a transparent shader with a diffuse/glossy shader to get the oceans transparent and the continents visible. I also use info nodes to control the material setting of the backfacing of the sphere the earth map is projected on. Initially I used a copy of the sphere with normals facing the inside, but the new set up is much cleaner and easier to control. The rest is simply keying a 360 degree rotation and exporting the images for the animation with alpha channels to use them. Of course the set up can be used for non-transparent oceans as well (giving you a stylish earth in a simple setting).
I also created a number of textures which enable me to control the material setting for separate continents. I am including some examples here:
As those texture influences are controlled through mix shaders, these can be keyframed, so you can change the colours fluently in an animation to e.g. highlight certain areas. The control through the textures is a bit cumbersome, as you have to create new textures for each of these effects, but you have almost 100% control – which is rewarding.
Here you can see the node set up.