Part of my dissertation is research of science blogs, and I finally have some results. I started with the relatively easy part of determining the language of science blogs and going to work my way to authors, journals, etc.
All the blogs in http://researchblogging.org/ that have 20 posts and above listed in the site and the last time they posted there was in 2010-2011. That was in order to make sure the sample is of established science blogs and relatively current.
Overall number of blogs: 189
English: 162 blogs (85.714%)
Spanish: 8 blogs (4.233%)
Portuguese: 8 blogs (4.233%)
German: 6 blogs (3.174%)
Polish: 3 blogs (1.587%)
Mixed (German and English): 1 blog (0.529%)
Chinese: 1 blog (0.529%)
No surprises here, English is definitely the language of science blogs (said the Israeli PhD student...).