This question is like a loop in my head that arises every now and then. I think and write clearly and quicker in my mother tongue that in English, but for me, entering a site in a language I don’t understand is one of the worse experiences I can get on the web today.
I found a post about it called //”[[http://ouriel.typepad.com/myblog/2005/05/should_you_blog.html|Should you blog in English]]”// where the author boils down the question to three factors: time availability, social ambition and scale. I totally agree with him, its an investment. Its all about how deep in the rabit hole you want to go.
I would say: go english unless you really don’t have any other option than to write in your mother tongue.