Geoberg has recently made another good post about many palaeontological orientated blogs with some of those written in Spanish. I also discovered two blogs (The Life of Madygen and NÖLOGIC) among Geoberg's post that are authored by German students of my former university. Additionally there is a newly born German language blog by a student of geophysics from my own university. It's called A long way to go but written in German (auf Deutsch!). These blogs are fairly new so I am just as curious as you are of what they will develop into.
The three "German" blogs were added to my feed of German Geoblogs that you can see on the right.