I know this is a really really long shot, but is it possible to change the camera's viewing angle, say center it on a ground location and look at the sky in some direction?

Currently Marble renders everything using software rendering. For reasons of performance our software renderer is optimized for bird's top-down view.

However an OpenGL view is in the works which should do what you are aiming for - once it's done: http://blip.tv/shenteys-show/opengl-in-marble-4372679

I guess shentey could give more information on this.